Replaced warnings when ARC was not enabled with errors - It's mandatory that CocoaLumberjack is compiled with ARC enabled (even if only for the CL files using -f-objc-arc).
Merge pull request #284 from bpoplauschi/arc_warnings_to_errors

Replaced warnings when ARC was not enabled with errors
Removed all the "C" log macros (as suggested in #220). By replacing sel_getName(_cmd) with __PRETTY_FUNCTION__, there is not need for the separation of Obj-C and C macros.
Updated the Mobile libtest project to demonstrate that it's working (had to use a formatter so the function/method names are used).