[VCS] const QVariant& localOrRepoLocationSrc

[dukju ahn]

some methods such as diff() and merge() takes QVariant as a
local or repository location. When the value is QString, no problem.
What matter is case of KUrl, since there is no native QVariant-api
to handle KUrl.

I think this one is candidate.
QVariant qVariantFromValue ( const T & value )

And we should allocate unique UserType, which is returned by
QVariant::userType().

Any comment?, if none I'll docuemt and define new enum for KUrl