Compile binaries also for earlier versions of Mac OS X
Make stm32flash work in Linux as well. Fixes to Makefile and serial flushing.
Merge pull request #1 from nakedible/master

Make stm32flash work in Linux as well. Fixes to Makefile and serial flushing.
Merge pull request #2 from Ell-i/master

Fixes for Mac OS X and Linux compilation