remove no more needed returning of the class constructor at end of class files

runtime.loadClass(...) no longer expects that eval(fileContent) yields
the constructor, and a few loaded files rely on that (e.g. all singletons/namespaces),
so let's be consistent
Merge pull request #606 from kossebau/removeNowUnneededClassReturning

remove no more needed returning of the class constructor at end of class files
Apply merged paragraph styles using OpSetParagraphStyle

Reduce the complexity within the remove text operation and push it up to
the controller instead.
Merge pull request #599 from peitschie/style-via-setstyle

Apply merged paragraph styles using OpSetParagraphStyle
Fix property removedProperties of ops.OdtDocument.signalMetadataUpdated

was passed as removedProperties.attributes: !string
instead of    removedProperties: !Array.<!string>

also
* reuse initial spec variable
* only deep clone opspec.setProperties, as removedProperties is cloned by
  opspec.removedProperties.attributes.split(',') already
Init removedPropertiesArray to null, is understood by OdfContainer.setMetadata
Add gui.MetadataController