go to end iter after each print_special_text if we don't have an argument with the iter where we have to insert text. See #7372

[Darlan & I]Improved BiDi support for banner text, popup with presence info and more status messages (kick, ban, change nick) fixes #7284 #7192

 - add option to show positive XEP-0184 ack in message window. Fixes 7341

common.latex was removed in r13821, so there is no reason to keep code which
imports it.

New gui_extension_point added. Do not use all args in remove_gui_extension_point() to identify elements to be removed. Use only first one

ability to connect to a server that doesn't support roster, and hide the correcponding features. Fixes #6745