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
Toggle/show/hide support for TextBlock
Toggle specs for all shape elements, fix for Shoes::Swt::Arc#toggle
Support toggle on Shoes::Swt::Button and Shoes::Swt::CheckButton
Pass on all shell arguments to CLI fixes #475 fixes #472
Support toggle on Shoes::Swt::Background
Use @real when toggling

Don't need to go all the way back to the @dsl.gui.real object. We're already
in the context of the @dsl.gui.
Spec toggle for Shoes::Swt::Image

Modified Shoes::Swt::Common::Toggle to allow @real to not support set_visible
as the SWT element for images don't have it. Toggling was already provided on
that class, though, in the underlying paint listener.
Don't attempt to set progress bar selection value if it has been disposed
Fix tests by adding disposed? => false to real stub in progress bar test
Add test to check that progress.fraction= doesn't set selection when real is disposed
Support toggle on Shoes::Swt::EditBox
Corrected home page to shoes4 in gemspec
Added license notice (MIT - already in the repo)
Updated after_do to version 0.2.2
Updated swt gem version
Oops we are actually describing a slot not a rect