Allowing re-parsing of inserted Pinterest links

Links added to the DOM, properly tagged for Socialite, would not be
re-parsed as buttons by the Pinterest script.  This commit adds a
'data-pin-build' attribute to the pinit.js script tag to expose the
parsePinBtns() function and replaces the reloadNetwork call with a call
to this function.

I am currently using my modified code at http://tilearray.com to change Pinterest button properties when a mosaic's owner makes changes via an AJAX call.  To demo:
<ol>
<li>Visit the site and make a mosaic</li>
<li>Click the Pinterest button to begin a share</li>
<li>Close the window without sharing</li>
<li>Add a title for your mosaic</li>
<li>Click the Pinterest button again</li>
</ol>

Let me know if I'm not doing something "the Socialite way".  :-)