remember last lines after reopening chat window (thanks Sergey Kuleshov, and don't fail on gtkspell-lang not available

gpg password is now saved 30 seconds when we enter it, so if it is used in several accounts, we don't need to enter the password twice.

(we can't force to not use TLS: bug in xmpp)

chat window now print when encryption in enabled / disabled and automatically activate/desactivate the gpg_toggle button

fixing #338 and the the already fixed widgets but in the same category in a glade way [eg. making them invisible from glade]

we can launch gajim with -v to enable verbose