Fix and simplify definition of GDK_PIXBUF_VAR:

Fix and simplify definition of GDK_PIXBUF_VAR:

2008-05-27  Michael Natterer  <mitch@imendio.com>

	Fix and simplify definition of GDK_PIXBUF_VAR:

	* Makefile.am: add -DGDK_PIXBUF_COMPILATION to INCLUDES.

	* gdk-pixbuf.c: don't #define it here. Remove GDK_PIXBUF_VAR from
	the definition of the version variables.

	* gdk-pixbuf-features.h.in: in the !G_PLATFORM_WIN32 case, always
	define GDK_PIXBUF_VAR to "extern". Remove redundant #ifndef
	GDK_PIXBUF_VAR around the whole block, the header itself already
	has include guards.

svn path=/trunk/; revision=20188