CRM-15256 : Repeating Events With Core Recursion

Fix includes points 1 - 9 from http://wiki.civicrm.org/confluence/display/CRM/Recurring+Events%3A+Implementation+Plan

To Summarize:
==================
Recursion library - When
Core Recursion and schema design, for recurring entities in general
Events: Create / generate, Update, and UI for Repeating Events. Parent-Child listing on manage event & dashboard, 
Search option to include participants from the repeating set of specified event.

Note: Code is in beta state. We 'll be doing more iterations to make it stable.
Would be good to get some feedback from core team early on.