XNAT-4210: Site Setup page works as requested (initialized:true) is set before...

XNAT-4210: Site Setup page works as requested (initialized:true) is set before showing the confirmation dialog, also moved site setup functions to /scripts/xnat/app/siteSetup.js; XNAT-4192: session timer works on all pages and DOESN'T RELY ON YUI ANYMORE; more reliable lookup of Spawner™ widget methods; added hooks in form input widgets to lookup a value via AJAX using syntax: 'value: ?$ /path/to/data | prop.name';