Rename PaddedStyle to AbstractStyle

Make Style inherit AbstractStyle, so it becomes the base class
of all styles. AbstractStyle also now has a default "data"
property so it's possible to conveniently declare helper
content inside styles.

Change-Id: Id84f3762cfae506e65021322619d7fb77b137994
Reviewed-by: Tomasz Olszak <olszak.tomasz@gmail.com>
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Removed reference to nonexistent file PageSlideTransition.qml.

Change-Id: I2b4a4369496d85829fb2de14078042c0a76f2aba
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Make styleHints a variant map

The styleHints are not really flexible enough as a stringlist
as we want to be able to pass actual properties. Since we already
have a properties member of the style we should move all of our
internal properties to that.

Change-Id: Id7a66ade243461f54c41b9ec89144668aaf19483
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Docs: fix missing/leftover docs, types, tags...

Task-number: QTBUG-31262
Change-Id: I6bf48604b9392a2a9c63c344363188a4693a8547
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Remove remaining references to PageStack

Change-Id: I59a9846c83340d0752659ef22cbb19a4be6a4129
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>