Abstract the sql_manager and cache_db stuff so that modules can utilize the core functionality to run their own instance of a cached SQL connection. Includes patch to fix some segs in case ODBC does not have password set or if using PGSQL support.

src/switch_core.c

@@ -2260,7 +2260,7 @@ SWITCH_DECLARE(int32_t) switch_core_session_ctl(switch_session_ctl_t cmd, void *
 		switch_time_calibrate_clock();
 		break;
 	case SCSC_FLUSH_DB_HANDLES:
-		switch_cache_db_flush_handles();
+		switch_core_cache_db_flush_handles();
 		break;
 	case SCSC_SEND_SIGHUP:
 		handle_SIGHUP(1);