re PR ada/14150 (Ada documentation out of date)

	PR ada/14150
	* Make-lang.in: Clean up generation of documentation

	* gnat-style.texi, gnat_rm.texi, ug_words: Resync with AdaCore version

	* xgnatug.adb: Removed, replaced by xgnatugn.adb

	* xgnatugn.adb: Replaces xgnatug.adb

	* gnat_ug.texi: Removed, replaced by gnat_ugn.texi

	* gnat_ugn.texi: Replaces gnat_ug.texi. Resync with AdaCore version

	* gnat_ug_unx.texi, gnat_ug_vms.texi, gnat_ug_vxw.texi,
	gnat_ug_wnt.texi: Removed.

From-SVN: r80308