GitLab

- create a OMEMOConnection class to mimic more how Gajim does things

HistoryWindow doesnt have a ChatControl

- In minimized MUCs we dont have a parent window
- use Gtks get_active_window() instead

- This is needed so url_image_preview works

Limit image preview to https and httpupload

See merge request gajim/gajim-plugins!47

- Remove parsing of OOB data, Gajim does this now

Minor fixes

See merge request gajim/gajim-plugins!48

UrlImagePreview python3/gtk3 port

See merge request gajim/gajim-plugins!46

- pylint/pep8
- Fix show/hide menubar
- Fix send status
- Update glade file to Gtk 3.18

Port Appindicator Plugin

See merge request !45