Add loggers for Vim and IDE

Added 3 loggers:
- Vim Logger, which just appends lines to the given log file
- IDE logger, which just writes to $stderr
- Fake logger, which doesn't do anything

We use Fake logger when debug mode is disabled, or for tests.

@os97673, could you please check it out, do you have everything you need for your RubyMine integration here? Or maybe you'd want to add/change something?

Thanks!