Fixed #227
Fixed #226
Merge pull request #229 from frmwrk123/fix/227

Fixed #227
Fixed #228

* Fixed visibility issue with CustomMenu
Merge pull request #230 from frmwrk123/fix/226

Fixed #226
Fixed #225

* Widget areas must have a unique name now
Merge pull request #231 from frmwrk123/fix/228

Fixed #228
Merge branches 'dev', 'fix/225', 'master' and 'dev' of github.com:frmwrk123/de.plugins-zum-selberbauen.ultimate into dev
Fixed #225

* Widget areas must have a unique name now
Merge pull request #232 from frmwrk123/fix/225

Fixed #225
Fixed #227

* These statements became obsolete by other fixes
Removed yet another obsolete use statement
Merge pull request #233 from frmwrk123/fix/227

Fixed #227
Fixed #224

* Removed exit where it was obsolete
* Replaced exit whenever possible with sth more senseful
* Added reasoning to the places where exit is required
Merge pull request #234 from frmwrk123/fix/224

Fixed #224
Ensured that empty data doesn't raise exception.

If a Category object is created with an invalid ID, an empty array is
given to handleData.
This added statement prevents an exception.
Fixed if statement.

* Removed obsolete `> 0`
Fixed importing of contents.

* Contents can now be imported without prior import of categories
Merge pull request #242 from frmwrk123/fix/241

Fixed #241
Resolved #243.