This allows to safely execute GUI code from other threads.

This is used in kwargs.rb and requires including Fox into global namespace elsewise.

Allow retrival of parts of the pixel data.

With the flag set, the icon would be free'd twice, first by the FXSplashWindow
and then by Ruby's GC.

Remove some comments, to only from C++ usable methods

Allow more consistent read/write access to image data, that is also
usable with derived classes like FXJPGImage.

Moreover much faster String based access to the pixel data is possible,
now.

FXImage#data and FXMemoryBuffer is now deprecated.

previous swig's #setData implementation wasn't really useable