In KParts we have both read only and read-write parts. Which is
mirrored from the document being read-only or not.
Introducing this concept into flake means we can use flake tools safely
on a read-only document without the user being able to change the read-only
document.

The new API will mean flake plugin writers have to specify read-only actions
in their call to KoToolBase::addAction().

svn path=/trunk/koffice/; revision=1124020