[patch] Allow log prefixes to be properly disabled when using custom logger

[felixmc]

See issue #14 EDIT: Moved to sails#4036.

These changes create the following behavior (I made sure to test each scenario described below):

Without a custom logger, everything should work the same, except that it only sets the default prefix if options.prefix is not false or null.

With a custom logger and no prefix defined, no prefixes are set and relies on the custom logger to handle its on prefixes (probably preferred behavior with most custom loggers).

With a custom logger and options.prefix defined to true it adds the default prefixes before passing the message to the custom logger (this option might result in duplicate prefixes like described in the issue if the custom logger has its own prefixes, but it would be useful if the custom logger did not have it's own prefixes).

With a custom logger and options.prefix is defined as a string, the string prefix is prepended to the message sent to the custom logger.

[Globegitter]

@felixmc is it possible to add a test for that scenario?

[RWOverdijk]

👍

[mikermcneil]

@RWOverdijk see balderdashy/sails#4036 (comment) for more recent discussion on it

[mikermcneil]

Update: I'm leaving this open pending balderdashy/sails#4036 (comment). If anyone would like to do that, please go ahead!

[luislobo]

@mikermcneil I think this one was pending a change in sails-docs that is already done. Probably can be merged?