Create easylogging++ wrap-around for explicit use in Splashkit core SDK

[njsch]

I'm a little surprised that Splashkit doesn't appear to have one of these yet to aid with debugging. Therefore, unless one is majorly missing something, I propose the following:

Use either structural / procedural (or preferably) object-orientated programming to create at least a basic logger utility (hierarchical?) to track program activity '(info, debug, warning, error, etc). Suggest the following specs:

• Preferably prioritise usage of single-header include to make things as easy as possible.
• Must be able to produce output to console or file.
• Must be at least mildly configurable i.e.
  • Flexible datetime timestamp for messages;
  • Different levels of log output, to the specified included and excluded log message categories.

I submit this proposal because I want to do some basic logging for my custom program for SIT102; however, I have had trouble using external dependencies such as boost/log; and I read that Boost is hard to compile on Windows anyway, which is my primary platform. Also tried Easyloggerpp but that didn't work either.

[hugglesfox]

Splashkit uses easylogging++ internally so I don't think it would be too hard to either expose it directly or to write a wrapper around it. If this is something @macite is interested in having in splashkit; I would be happy to make a PR.

[njsch]

@hugglesfox, Ah. Didn't know that SK already utilised this. Thanks for the pointer.

[njsch]

@hugglesfox, So in Splashkit core there is a very short C++ source file in ./coresdk/src/backend. Is that all the support there is so far?