2008-11-12  Tor Lillqvist  <tml@novell.com>

	Bug 556415 - Crash on Windows 2000 in g_winhttp_vfs_init()

	* win32/gwinhttpvfs.h: Move the set of function pointers to
	winhttp.dll into a separate struct GWinHttpDllFuncs. Just have a
	pointer to that in the GWinHttpVfsClass.
	
	* win32/gwinhttpvfs.c: Move the lookup of functions from
	winhttp.dll into a function of its own, that stores the pointers
	in a separate GWinHttpDllFuncs variable. Add two bookeeping
	booleans lookup_done and funcs_found.

	Don't call g_io_extension_point_implement() to register the
	winhttp extension unless winhttp.dll has been successfully loaded
	and the required functions found in it.

	* win32/gwinhttp*.c: Adjust calls of the functions looked up from
	winhttp.dll correspondingly.


svn path=/trunk/; revision=7648