ARMORY-190 - Armory is unable to call Objective-C code on OS X

Checking in super-duper-experimental code meant to re-enable notifications on OS X 10.7 when using Growl. The code doesn't seem to work yet and may get removed later. Also fixed a Makefile issue that caused "make clean" to fail.
Merge branch 'devel' of https://github.com/etotheipi/BitcoinArmory into devel