Hide ftw.mail.mail-in viewlet, yet again.

Plonetheme.teamraum has its own skinname, thus we need to remove the viewlet for
that skin as well.
AdminUnit table: Added upgradestep for the new abbreviation column.

See https://github.com/4teamwork/opengever.ogds.models/pull/24 for more informations.
Referencenumber: use current admin_units abbreviation instead of the label for the PloneSite part.
PEP8.
Merge pull request #600 from 4teamwork/pg_abbreviation_column

PloneSite referencenumber: use current admin_units abbreviation instead of the label.
Merge pull request #602 from 4teamwork/deif-hide-mail-in-viewlet

Hide ftw.mail.mail-in viewlet, yet again.
Fix printing error message for dossiers with non-unicode chars in title.

Fixes #589.
Merge pull request #603 from 4teamwork/deif-fix-deactivate

Fix printing error message for dossiers with non-unicode chars in title.
LaTeX layout: use current admin_units label instead of the current org_unit as client title.
Merge pull request #604 from 4teamwork/pg_latex_client_title

LaTeX layout client title: use current `AdminUnits` label.
Use ftw.table from source.
Treeportlet: define context-url data object instead of context-path.

This is a follow up of #596: During the changes to support virtualhostmonster configurations, the tree data has changed from path to url. But to adjust the data attribute, was forgotten.

Additional i've added some small tests for the treeportlet itself.
Merge pull request #605 from 4teamwork/pg_treeportlet_current_selector_fix

Treeportlet: define context-url data object instead of context-path.
Merge pull request #606 from 4teamwork/deif-use-source-ftwtable

Use ftw.table from source.
Use plone.formwidget.autocomplete from soource.