Correctly sort metacontact data if one of the jids is a transport and not in our roster. Fixes #4208, #4195.

 * 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.

Remove some usage of has_key() in the contacts module. It is a bit slower (method overhead) and will be deprecated soon.
In roster_window. make a small if-clause more pythonic.

Correctly count metacontacts in non merged accounts mode if we have metacontacts over several accounts.

Remove timing information for roster drawing.

Do not update metacontacts when nothing has changed. Fixes sending metacontact info to server when we expand a groupchat.

* Added NS_RECEIPTS to protocol namespace list.
* Show our support of XEP-0184 in caps.
* Added a big, fat warning to get_contact as this does not work as
  expected.
* There was some strangeness in our XEP-0022, it added an id tag to
  the x tag, which isn't mentioned anywhere in the XEP. And for some
  strange reason, that id even was the same all the time.
* Fixed a typo.

 * Change metacontact ordering. Fallback to priority only if two contacts have the same show, not the other way round.
 * Move contacts that just signed out to the bottom of the group, not to the top.

-Use a method to get_shown_groups (possibly more work to do (special group attribute))
-Show contact only if contact.ask, not according to modified xep 0162 logic. (I don't get neither the xep
meaning, neither this modified logic, can you explain steve-e ?)
-Remove contact before we modify it req_sub(). Else we can't remove it because iter is not found.
-When removing a contact and we let him in see us (observer), manually set show to offline, so he is not set as
visible.
-Remove observer from observer group if we asked him auth (I mean before he answer). Xep 0162 say he is not an
observer then. Fix contact staying in observer group when we get auth later.
-Renaming groups seems fixed (it's an accident :p )

More work on group to follow

-When creating self-contact contact instance, store it with group 'self_contact', so it never goes in General
-Make general group not be seen visible because of self contact even if self.regroup
-Remove the self contact instance itself too when WE deconnect or when IT deconnect, so we will
not see it as offline if refilling roster (regroup account for example)

Fixes #3893.

Contacts are now online hidden when they connect/reconnect and not completely removed/readded. Should come with a great speed improvement for people with big rosters.
There are still a few known problems but non that should dalay this patch any longer. Related bugs will be tracked with 'modelfilter' keyword.

See #1201

Compute metacontact big brother by comparing them instead of computing an absolute score for each one