* libltdl/ltdl.c (FILENAME_MAX): use it instead of MAX_FILENAME,

	* libltdl/ltdl.c (FILENAME_MAX): use it instead of MAX_FILENAME,
	and don't redefine it if already defined; default to 1024, as on
	most systems
	(LT_SYMBOL_LENGTH): renamed from MAX_SYMBOL_LENGTH
	(LT_SYMBOL_OVERHEAD): new macro, that accounts for the size of
 	the _LTX_ separator and the initial underscore
	(lt_dlsym): sym now points to a stack buffer (lsym) if possible,
	or is dynamically allocated.  If allocation fails, a
	buffer_overflow_error is returned.