New handle flip implementation.
* Handles flip when:
- Cross each other.
They can flip as soon as they cross or when the handles are released.
Text::Decorator::FlipSelectionHandlesOnCrossEnabled()
- According the character's direction.
- If they exceed the boundaries of the decoration area.
* The bounding area is stored in world coords.
There is no need to store it in actor coords and then transform it on every query.
* Fixes a crash when selection handles are crossed and text is inserted.
Change-Id: Ie0ec8174cb5f34c17f96d7179fcdc3cf05bc2df8
Signed-off-by: Victor Cebollada <v.cebollada@samsung.com>