Change variable name from base_url to site_url

So it's more in-line with other global context variables ie.
`site_name`.

See https://github.com/bartTC/dpaste/pull/89#issuecomment-285331008

dpaste/context_processors.py

@@ -2,7 +2,7 @@ from django.conf import settings
 
 def dpaste_globals(request):
     return {
-        'base_url': getattr(settings, 'DPASTE_BASE_URL', 'https://dpaste.de'),
+        'site_url': getattr(settings, 'DPASTE_BASE_URL', 'https://dpaste.de'),
         'site_name': getattr(settings, 'DPASTE_SITE_NAME', 'dpaste.de'),
         'jquery_url': getattr(settings, 'DPASTE_JQUERY_URL',
             'https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.js'),

dpaste/templates/dpaste/about.html

@@ -37,14 +37,14 @@
     on this page</a>. For a quick start here is a code example (Python 2.x):</p>
 
     {# Just put the script in dpaste and copy the source node #}
-    <div class="code python"><ol><li id="1"><span class="c">#!/usr/bin/env python</span></li><li id="2">&nbsp;</li><li id="3"><span class="kn">from</span> <span class="nn">urllib</span> <span class="kn">import</span> <span class="n">urlencode</span></li><li id="4"><span class="kn">from</span> <span class="nn">urllib2</span> <span class="kn">import</span> <span class="n">Request</span><span class="p">,</span> <span class="n">urlopen</span></li><li id="5"><span class="kn">from</span> <span class="nn">sys</span> <span class="kn">import</span> <span class="n">stdin</span></li><li id="6">&nbsp;</li><li id="7"><span class="k">def</span> <span class="nf">paste_code</span><span class="p">():</span></li><li id="8">&nbsp;&nbsp;&nbsp;&nbsp;<span class="n">request</span> <span class="o">=</span> <span class="n">Request</span><span class="p">(</span><span class="s">'{{ base_url }}/api/'</span><span class="p">,</span> <span class="n">urlencode</span><span class="p">({</span></li><li id="9">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'content'</span><span class="p">:</span> <span class="n">stdin</span><span class="o">.</span><span class="n">read</span><span class="p">(),</span></li><li id="10">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'lexer'</span><span class="p">:</span> <span class="s">'python'</span><span class="p">,</span></li><li id="11">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'format'</span><span class="p">:</span> <span class="s">'url'</span><span class="p">,</span></li><li id="12">&nbsp;&nbsp;&nbsp;&nbsp;<span class="p">}))</span></li><li id="13">&nbsp;&nbsp;&nbsp;&nbsp;<span class="k">print</span> <span class="n">urlopen</span><span class="p">(</span><span class="n">request</span><span class="p">)</span><span class="o">.</span><span class="n">read</span><span class="p">()</span></li><li id="14">&nbsp;</li><li id="15"><span class="k">if</span> <span class="n">__name__</span> <span class="o">==</span> <span class="s">'__main__'</span><span class="p">:</span></li><li id="16">&nbsp;&nbsp;&nbsp;&nbsp;<span class="n">paste_code</span><span class="p">()</span></li></ol></div>
+    <div class="code python"><ol><li id="1"><span class="c">#!/usr/bin/env python</span></li><li id="2">&nbsp;</li><li id="3"><span class="kn">from</span> <span class="nn">urllib</span> <span class="kn">import</span> <span class="n">urlencode</span></li><li id="4"><span class="kn">from</span> <span class="nn">urllib2</span> <span class="kn">import</span> <span class="n">Request</span><span class="p">,</span> <span class="n">urlopen</span></li><li id="5"><span class="kn">from</span> <span class="nn">sys</span> <span class="kn">import</span> <span class="n">stdin</span></li><li id="6">&nbsp;</li><li id="7"><span class="k">def</span> <span class="nf">paste_code</span><span class="p">():</span></li><li id="8">&nbsp;&nbsp;&nbsp;&nbsp;<span class="n">request</span> <span class="o">=</span> <span class="n">Request</span><span class="p">(</span><span class="s">'{{ site_url }}/api/'</span><span class="p">,</span> <span class="n">urlencode</span><span class="p">({</span></li><li id="9">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'content'</span><span class="p">:</span> <span class="n">stdin</span><span class="o">.</span><span class="n">read</span><span class="p">(),</span></li><li id="10">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'lexer'</span><span class="p">:</span> <span class="s">'python'</span><span class="p">,</span></li><li id="11">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="s">'format'</span><span class="p">:</span> <span class="s">'url'</span><span class="p">,</span></li><li id="12">&nbsp;&nbsp;&nbsp;&nbsp;<span class="p">}))</span></li><li id="13">&nbsp;&nbsp;&nbsp;&nbsp;<span class="k">print</span> <span class="n">urlopen</span><span class="p">(</span><span class="n">request</span><span class="p">)</span><span class="o">.</span><span class="n">read</span><span class="p">()</span></li><li id="14">&nbsp;</li><li id="15"><span class="k">if</span> <span class="n">__name__</span> <span class="o">==</span> <span class="s">'__main__'</span><span class="p">:</span></li><li id="16">&nbsp;&nbsp;&nbsp;&nbsp;<span class="n">paste_code</span><span class="p">()</span></li></ol></div>
     <br/>
 
     <p>Save this script in <code>/usr/local/bin/dpaste</code> and give it the executable bit: <code>chmod +x /usr/local/bin/dpaste</code>.</p>
     <p>Usage: <code>cat foo.txt | dpaste</code></p>
 
     <p>An alternative would be to just use <code>curl</code>:
-    <code>alias dpaste="curl -F 'content=&lt;-' {{ base_url }}/api/"</code></p>
+    <code>alias dpaste="curl -F 'content=&lt;-' {{ site_url }}/api/"</code></p>
 
 
     <h3>Applications using the API:</h3>
@@ -84,7 +84,7 @@
     </p>
     <p>
         Type the 4 letter code of your snippet in the field and submit.
-        Like this yellow one here: <tt>{{ base_url }}/<strong>SiZrT</strong></tt>
+        Like this yellow one here: <tt>{{ site_url }}/<strong>SiZrT</strong></tt>
     </p>
 
     <form method="POST" action="{% url "snippet_delete" %}">