show only once unread messages at startup when we have twice the same contact in 2 accounts. Fixes #2921

* we now handle roster push and roster reception
* changed version number in src/common/defs.py

 * remove js from some headers
 * set coding:utf-8 to allow real names in headers

 * Remove some licencing problems
 * To do: same for images
 * See #4200

we have that in all files. To at least lesser the confusion a bit, add
vim tags for that.
Additionally, fix wrong #! in a few files.

when the defs.py file is changed.

launch. This is necessary because with a big history get_last_date_that_has_logs
can take about 5 seconds on first launch.
Created new gajim subversion.

create caps_cache if it doesn't exists (can happen if logs.db is created in 0.11.2 version). fixes #3512