Some fixes with the db multi-query changes:
Some fixes with the db multi-query changes:

db::run_batch() checks if we're in a transaction, and if so, sets $use_master = true; since we always default to
master when in a transaction.

db::determine_query_server() now checks db::$replication, and if false, just returns 'slave' by default.

db::_query() now uses db::determine_query_server() instead of its own code. determine_query_server is now the
one abstracted function for checking where a query should be run.

lyonbros/a-frame