Updated colors and runtime platform, further work on issue #28

* clusterd.py
  src/core/state.py
  -- Added the platform variable to determine what platform we're
  currently running on.  This is currently used to determine if we
  should colorize output.
* src/core/utility.py
  -- capture_input now returns an empty string on error, instead of None
  -- Modified coloring in the Msg() function