Revert "CRM-14423 - Call setMySQLTimeZone as part of Civi's bootstrap"

This reverts commit 309cd470a1c69b44b2d4c0651b62950a7223ddcc.
Merge pull request #2868 from totten/master-revert-tz

Revert "CRM-14423 - Call setMySQLTimeZone as part of Civi's bootstrap"