Bug fix: no_owner (addProject) requires a type to be provided as part of the xml

[MRdNk]

no_owner requires the xml element to look like this:

<no_owner type=\"boolean\">false</no_owner>

This patch, adds the ```type=\"boolean\" for no_owner; and lays groundwork for others that require this type attribute.

Probably a neater way to do it, but this fixes the bug.

[MRdNk]

I've put something up on the Pivotal Labs community about getting rid of this requirement. http://community.pivotaltracker.com/pivotal/topics/addproject_no_owner_attribute?rfm=1

[stelcheck]

Thanks for your contribution! To me this is fine for now I think.