Added icon/text column fields to sgui_icon_view

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
[cleanup] moved misc. window flags to single flag field

Sorry to break the ABI and API at the same time (altough we don't have a
stable release anyway, but I was told some people actually use this).

Up to now, the window had various flag parameters (resizeable, double
buffered, etc...) now they were united to one single flag field.

Pros:
 - Cleaner code
 - Can be extend in the future without breaking the ABI

Cons:
 - Had to break ABI & a little bit of API introducing it

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
[cleanup] made message box use DIALOG_REJECTED event

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
Added more verbouse comments to sample programs

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
Removed misc. macros from doxydoc, added latex output

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
updated documentation

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>