I simplified a lot of API calls by pulling panel memory management
inside the library. All API calls which previously required a panel
as parameter are now handling their panel themself.
This is a breaking change which fixes bad closing behavior in
non-blocking popups. If the maximum size of a non-blocking popup was
not reached and you clicked to close the popup under it could happen
that it wouldn't be closed. This is now fixed in combination with
more popup control by allowing to set both the maximum height as
well as popup width.
This commit fixed some bugs from the last commit as well as some general
changes and fixes of some old bugs. For overview of all changes please
look inside `CHANGELOG.md`.
This commit adds a GWEN UI style skinning example. It is
certainly not perfect right now (especially windows suck) but
it is probably useful for a general overview. One thing that is
pretty clear for me now is that I need a way to read in a style from
file or memory since manually setting up properties, colors
and images is quite a pain.
