don't prevent removing contact iter in groupchat if there are pending event with an opened chat window. Fixes #4340

handle XEP-0203 (Delayed Delivery) and use it when forwarding unread messages via adhoc commands. Fixes #4347

use spec version instead of program version to determine which spec to use for notification-daemon. Fixes #4126

don't remove contact instance when we remove last event if a chat is stil opened, but when we close the window. Should fix #4272

 - Many punctuation fixes
 - remove "please" (like in the GNOME project).
	The translation guidelines at
	http://gnome.org.ru/wacko/TranslationPrinciples
	warn against using "пожалуйста" (please)
	in Russian technical texts.
 - change voice/aspect of some verbs
 - Fix a space before bang in a string.
	AFAIK, French is the only language to use " !",
	all other languages use exclamation marks without
	spaces (certainly true for English!).