Applied patch to allow passing stdlib scons flag
Merge branch 'master' of https://github.com/mixxxdj/mixxx into osx_build_fixes
Remove unnecessary code which breaks compile on other than linux.

The thread cpu timer is adopted from performance timer code for
linux. There is no implementation for other platforms, but the old
functions were left around leading to duplicate symbols when linking.

Removed these and renamed 'default' dummy functions.
Merge branch 'osx_build_fixes' into hile