option to define it.

new add contact window. TODO: enable the register button when our server have this transport. Fixes #872

prevent a TB and print an error message to the user when he/she tries to et a non valid nickname in a room

privacy lists open / delete buttons are not unsensitive when we open the window and no privacy lists is available. Fixes #2140

when we open a second tab and conversation textview was scrolled down in the forst one, scroll it down after we show tabs. Fixes #2190

reset focus_out_end_iter_offset var when we clear the textview. Fixes #2175

we now detect loop when server isn't RFC complient and handle badly subscription acknoledgment. Fixes #1864

del keys now work when multiple selection (this way we can remove several transports at the same time). For #1514