* maint.exp: Raise timeout to give Cygwin targeted GDBs more time

	for printing symbols and statistics.
	Add test for using relative pathnames in "maint print msymbols" test.
	Mark "maint info sections DATA" XFAIL on Cygwin.
	Remove Cygwin XFAIL mark on "help maint dump-me" and "maint dump-me"
	tests.