km_KH locale: remove tags which were using Lao characters [BZ #13953]

km_KH locale: remove tags which were using Lao characters [BZ #13953]

	[BZ #13953]
	* localedata/locales/km_KH: Use ASCII as much
	as possible for better readability of the source and
	remove useless comments.
	* localedata/locales/km_KH (LC_TIME): Remove era stuff, it
	was commented out and apparently wrong anyway because it was
	using Lao characters. If Buddhist era should be used
	for km_KH, a native speaker should write the correct formaat
	for Khmer.
	* localedata/locales/km_KH (LC_TIME): Add first_weekday 1
	(According to CLDR, the first weekday for Cambodia is Sunday).
	* localedata/locales/km_KH (LC_NAME): Remove name_mr and name_mrs
	(These were using Lao characters which must be wrong. If we get
	the correct data from a native speaker, we could add it back, until
	then it is better not to have name_mr and name_mrs at all than
	having it wrong).