2013-10-14  Robert Dewar  <dewar@adacore.com>

	* gnat_ugn.texi: Document -gnateu switch.
	* opt.ads (Ignore_Unrecognized_VWY_Switches): New switch.
	* stylesw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.
	* switch-c.adb: Implement -gnateu (sets
	Ignore_Unrecognized_VWY_Switches).
	* validsw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.
	* warnsw.adb: Ignore unrecognized switch if
	Ignore_Unrecognized_VWY_Switches set.

From-SVN: r203536