(which are subtlely different to 24-bit), instead of assert-dying
  due to the pixmaps having alpha channels by default
  - We use a very nasty technique -- disable XRENDER.  As a result,
    all of KolourPaint looks crap.  If I have time, I'll fix this
    properly.
  - Add kpPixmapFX::has{Mask,AlphaChannel}() which have special 32-bit
    screen handling

CCMAIL: Pino Toscano <toscano.pino@tiscali.it>


Other changes:

* Add kpPixmapFX::initMaskOps(), which is called by the new kpPixmapFX::init(),
  which is called by kolourpaint.cpp:main()
  - Includes the disable-XRENDER hack
  - Compile-time #warning that KolourPaint only works on X11
  - Move kolourpaint.cpp paletted-screen warning into here
    - This helps to centralize the alpha-related hacks

* Instead of assert-crashing the program on KP_PFX_CHECK_NO_ALPHA_CHANNEL,
  simply kError() [configurable without recompiling all of KolourPaint by
  changing the return value of the new kpPixmapFX::checkNoAlphaChannelInternal()]

* kpPixmapFX::ensureOpaqueAt()
  - Fix bogus check for whether a mask does not exist
  - Cache the mask

* Rename kpPixmapFX::convertToImage() to kpPixmapFX::convertToQImage()

* kpPixmapFX:
  - Document more fully the paint engine assumptions (regarding no-alpha-channel)
  - Style

* Use "image"/kpImage instead of "pixmap"/QPixmap for document image data

* kpMainWindow_File.cpp: compile-time warning that wallpaper setting is not
  implemented for non-X11

* kpImage:
  - Make kpImage a class instead of a typedef, to slowly migrate to an opaque
    kpImage (for the future image library)
  - +APIDoc

svn path=/trunk/KDE/kdegraphics/kolourpaint/; revision=713884