Make 'rake spec:swt' also run shoes specs with swt backend
Require app parameter for Oval

Also, move oval arg parsing to ElementMethods, because that is part of
the DSL.
Remove unused code
Set default size and add Swt::ModifyListener for Shoes::EditLine and Shoes:: EditBox elements. Try out a tiny test snippet:

Shoes.app do
  edit_line{|e| p e.text}
  edit_box{|e| p e.text}
end
Fixed a typo.
Renamed a class name from Shoes::List_Box to Shoes::ListBox. Set the default size and added Swt::SelectionListener for Shoes::ListBox. This is a simple test snippet:

Shoes.app do
  list_box items: [1,2,3,4,5] do |e|
    p e.text
  end
end
Require app parameter for Line
Require app parameter for shape
Remove unused Shoes::Swt::ElementMethods
Add Swt::Shape specs
Expand common painter setup to work for Shape
Cleaned up background.rb a bit.
Added instance variable @container to use Shoes::Swt::Common::Move#move method. This test snippet works now.

Shoes.app do
  o = oval 0, 0, 100, 100
  animate{|i| o.move i, i}
end
Revised some specs for this commit: https://github.com/shoes/shoes4/commit/7b8d217bca176f4e89df783012eb6be53c81ea69
Add #rect to DSL, along with Swt implementation

- allows for the following calls:
  - rect 10, 10, 50 # => square
  - rect 10, 10, 50, 100 # => rectangle
  - rect 10, 10, 50, 100, 12 # => rectangle with rounded corners
  - rect :left => 10, :top => 10, :width => 50, :height => 100,
         :corners => 12 # => rectangle with rounded corners
Add specs for movable oval
Add Rect#move
Remove outdated comments from Oval
Change oval's radius parameter to diameter
Implemented Shoes::Swt::Common::Clickable#clickable method. It makes Shoes::Image, Shoes::Oval and Shoes::Rect elements clickable for now. Try out a sample snippet:

Shoes.app do
  o = oval(0, 500, 100){p 'clicked oval'}
  img = image('static/shoes-icon.png'){p 'clicked image'}
  r = rect(500, 0, 100){p 'clicked rect'}
  animate do |i|
    img.move i, i
    r.move 500-i, i
    o.move i, 500-i
  end
end