The reason for adding 'DomainMapper' is to be able to check
during import in these classes whether or not the import is
in a 'styles.xml' file or not.

Also added blank handling for new XML nodes.

Reviewed on:
	https://gerrit.libreoffice.org/10870

Change-Id: Ib2acde736d96f30eda40ee327991dc6ae0ed7f25