[ale] added api to batch logger config compilations

It's now possible to wrap ale (re)configurations with call to
ale:with_configuration_batching/1. Within "body" of that call all ale
compilation is delayed and at the end of that call all loggers are
recompiled.

Using that API allows setup of complex ale log topologies without
overhead of recompilation on every call to ale:add_sink and
ale:set_loglevel.

Change-Id: I850f02060b6957fec9d295ecd3c427d81abe7e36
Reviewed-on: http://review.couchbase.org/42358
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>