Fix DebugAnalyzer gcc 4 build
Use doxygen style comments as per guidelines

Thanks Axel!
GIFTranslator: Reorder includes

Thanks Jérôme
GIFTranslator: Refactor filling out BBitmap

* Remove the NULL check since BBitmaps don't return NULL but check
  that it IsValid() instead.
* Fill out the *out pointer directly instead of creating a temporary
  bitmap pointer.
* Rename err to result.
* Return B_OK unconditionally if we get to the end of the function.

Thanks again Jérôme