RIOT-OS/RIOT — pull request #1367 by Kijewski (2014-07-03 17:15:43+00:00)
Title: make: introduce source file blacklisting

**UNTESTED, WIP**

Right now RIOT compiles in every source file it finds in the module
directory, unless the files were specified in `SRC` / `SRCXX`.

This PR adds the variables `SRC_BLACKLIST` and `SRC_WHITELIST`, which
might come in handy if your have conditional or mutual exclusive source
files as in #1350.