second source field mapping dissapears

the main issue here was that in step 2 of the upload process, when adding metadata mappings,
categories or item specific categories with the + button; they were added with javascript. if the
user stepped back in the upload process, e.g., from step 3 back to step 2, those added fields
would be lost.

the solution implemented was to use javascript and cookies to maintain the state of those added
fields and re-apply them if the user comes back to step 2.

* includes/Config.php
  - added resource jquery.json so that it can be used in the js createCookie() method

* includes/Forms/MetadataMappingForm.php
  - added ids to form tables for quicker js access to the individual tables

* resources/js/ext.gwtoolset.js
  - added line breaks to code that is > 100 characters
  - added logic to handle cookies
    + createCookie()
    + removeCookies()
    + restoreJsFormFields()
    + storeJsFormFields()
  - alphabatized initial gwtoolset variables
  - attempted to improve the option search while still using jQuery
  - changed .html() to .append() when adding jQuery objectsto an html element
  - fixed an issue where the restore of js fields did not always correspond with field/values
    previously present in the form
  - re-worked the logic of handleButtonAddClick() and handleFormSubmit() so that they work
    in conjunction with the new cookie handling methods

* re: assembla/169 - Second source field mapping disappears

Change-Id: I7afe3d2fb01becccd586afed2ead490dbcd01784
Merge "second source field mapping dissapears"