Refactor HLListWidget setupKeyBindings
Rename HLRepeatingKeyBinderForWidget to HLRepeatingKeyBindingHandler.
instvar
  keysWithActions to keyBindings
class method
  newWithWidget: to forWidget:
methods
  whileKeyPressed:doAction: to whileKeyPressed:do:
  resetKeypressActive to handleKeyUp
Merge pull request #507 from rcsimm/helios-sunit

Refactor HLListWidget setupKeyBindings