Move pending upgrade check to core class from config. Decouple core from config (doesn't extend config anymore)

Fix bug where setting overwrote all config rows because of missing where clause - (hint: multiple configs coming...)

Feature/datepicker

Feature/inline notes

Feature/ajax urls revisited

Fixing the 'Fetch Email' features

Reviewed By: Peter Rotich 04/26/12

Correcting the if-statement for message delete and move.

'msg_id' is no longer the field name in TICKET_EMAIL_INFO: changed to 'message_id'. 
TICKE_THREAD_TABLE was corrected to TICKET_THREAD_TABLE.

Updating main.inc.php: File did not include a define statement for TICKET_EMAIL_INFO_TABLE used by include/class.ticket.php

Updating include/class.config.php: canFetchMail was not checking for the proper database field name in the config table.