Manager now propagates ESC key press to controllers.
Substituted "if" by an "assert" on expand function of Graphics.
Removed condition on reset_size of widget.
Privatized focus and hover of Manager.
Removed hit_test from Rectangle, and added it to specific Controllers.

This removes a Controller functionality from a geometric object.
Made Slider._set_knob_pos a public method.
Fixed error on document's hit_test.
Added is_inside method to Rectangle and used it on hit_test method.
Fixed error on reset_size on which dialog called non-existent parent.
Fixed error on which layout was called more than needed.

- Removed layout from widget's reset_size

- Added layout to after each reset_size after events.
Added missing hit_test to text_input.
Minor change to style.
Added layout() back to reset_size() because size can change layout.
Label now uses "text_color" and not "gui_color".
Abstracted theme to not depend on default values.
Minor fix to style.
Fixed error causing two calls of layout() in button.
Fixed error on Folding that caused parent not to be set to children.
Focus now uses its own theme's path.
Updated all examples to new pyglet's theme.