removed no_swt in button_spec

* we want al the tests to run with all the backends
Removed the guard file (funtions were unused

* moved configuration of stubbed SWT event loop into the accurate
  SWT spec helper, so it gets done every time and we don't nee
  to check for the backend
* guard file removed because the backend_is thingy was/is unwanted
  if you ask me
* Also didn't need all the operating system is something thingies
Merge branch 'RemoveGuard'
Reintroduce treat symbols as true values rspec config