(FR #917) Never use Drupal db connection on Civi tables

Unfortunately, we need to go in this direction to use DB transactions.

Change-Id: Iff0c2617b12693330f002e8323509f4dcc77968d

Conflicts:
	sites/all/modules/queue2civicrm/recurring/recurring.module
Protect schema upgrades

Change-Id: I80d620b28177727485ae922dddc13c3d7af6849d
Make a schema upgrade more idempotent

Change-Id: Ic378f5f7cb18b5b9764c77cf252af1921407ead3
Bugfixes and error handling for commit dcbfae0f15689b2e48cc811af6db04ce5a3ca10f

Change-Id: Ic5901b2876de1bd58ddcd29aeaf393bdfa38f76e
(FR #1249) Make schema match production

Change-Id: Ia2ad7edc745ae050b2b47a15984e328c3f22b28f
(FR #917) Convert dangerous queries to strictly use the Civi db connection

Change-Id: Ie4f2271ca42dd5fe81fd553dd29140e320e3ce04