add support for specifying the domain type in the zone template.

Currently when creating a domain from a template the domain type will always be 'NATIVE' and drop-down menu for type is ignored.
This commits allows to specify the type (and master for type SLAVE) in the zone template and the domain will be created accordingly.
Merge pull request #50 from databus23/add_type_to_template

add support for specifying the domain type in the zone template.