Add New Glossary Page And Developer Search Feature

This commit adds the code necessary to generate a new
en/developre-glossary page with entry pages in the en/glossary/
directory, e.g. en/glossary/51-percent-attack.

The glossary page and the individual term pages feature a JavaScript
search engine (no CGI) for just glossary terms.  This search box has
also been added to the following pages:

    * Developer Documentation (the index page)
    * Developer Guide
    * Developer Reference
    * Developer Examples

The search box requires the following MIT-licensed libraries:

    * JQuery
    * JQuery UI
    * JQuery UI CSS stylesheet

These allow our JS code to be almost trivially simple in js/devsearch.js

This commit adds only code.  Actual glossary entry data will be added in
a subsequent commit.

en/developer-examples.md

@@ -7,6 +7,7 @@ lang: en
 id: developer-examples
 title: "Developer Examples - Bitcoin"
 ---
+<link rel="stylesheet" href="/css/jquery-ui.min.css">
 
 # Bitcoin Developer Examples
 
@@ -26,6 +27,8 @@ title: "Developer Examples - Bitcoin"
 
 {% include fragment_reviews_needed.md %}
 
+<input id="glossary_term" placeholder="Search the glossary, RPCs, and more">
+
 {% include example_intro.md %}
 
 {% include example_testing.md %}
@@ -37,8 +40,12 @@ title: "Developer Examples - Bitcoin"
 {% include example_p2p_networking.md %}
 
 {% include references.md %}
+{{site.glossary_links}}
 
 </div>
 
 <script>updateToc();</script>
 <script>addAnchorLinks();</script>
+<script src="/js/jquery-1.11.2.min.js"></script>
+<script src="/js/jquery-ui.min.js"></script>
+<script src="/js/devsearch.js"></script>