add remaining template options for date extraction

see also: https://github.com/rsyslog/rsyslog/issues/65

Conflicts:
	runtime/msg.c
	template.c
add date-wday template option to complete date-related set

Was not requested, but makes sense to support it.
See also: https://github.com/rsyslog/rsyslog/issues/65

Conflicts:
	ChangeLog
	template.h