Added a few specs to increase test coverage
removed the repeated app.stubs
Moved general specs over from dsl_spec to the DSL specs

* we run all the specs under spec/shoes/ with every backend
  e.g. mock and SWT so they work for both
* the specs I left in dsl_spec are SWT specific due to the
  add_painter asserties which is an SWT thing
we decided some time ago to use it instead of specify