Update version to 1.6a1-dev.
Merge pull request #1133 from normanjaeckel/SplitMaster

Update version to 1.6a1-dev.
New API for widgets using a metaclass.

It is now possible to define a default state and to submit extra stylefiles and javascript files when defining a widget in an app. This is done by a new metaclass in openslides.utils.dispatch. Also fixed some other tests.
Merge pull request #1134 from normanjaeckel/NewWidgetAPI

New widget api
remove the last occurence of gnu gpl license header fix #1130
Merge pull request #1139 from DerPate/fix_last_gpl_header

remove the last occurence of gnu gpl license header fix #1130
Move widget test to correct directory.
Disable participant widgets by default. Fixes #988.
Merge pull request #1142 from normanjaeckel/MoveTest

Move test
Merge pull request #1144 from normanjaeckel/DeactivateParticipantWidgets

Disable participant widgets by default. Fixes #988.
Enable update and delete view for uploader refering to his own files.
Merge pull request #1147 from normanjaeckel/EditOwnFiles

Enable update and delete view for uploader refering to his own files.
Change API for plugins, esp. for names and versions of plugins. Also enhance possibility to patch existing OpenSlides urlpatterns.

Fix some other tests by the way.
Merge pull request #1143 from normanjaeckel/PluginAPI

Change API for plugins, esp. for names and versions of plugins. Also enh...
Rename classes in the config api.

Also change attributes for config collection without view.
Merge pull request #1145 from normanjaeckel/ReworkConfig

Rework config
Rename some classes of the poll api. Clean up the poll api.
Merge pull request #1146 from normanjaeckel/ReworkPoll

Rename some classes of the poll api. Clean up the poll api.
Inserted api for the personal info widget.
Merge pull request #1149 from normanjaeckel/PersonalInfoClass

Inserted api for the personal info widget.