Port DVcsPlugin away from KDialog
Remove lookup
Fix closing documents

Otherwise we were trying to remove the same view twice and it got
quite brutal.
Prefer local files in IncludeNavigationContext.

Removes the overly verbose file:// prefix from navigation popups.
Close container tabs on middleclick again.
Remove TODO message, this is correct imo.
Set text hint delay to old value.

This brings back the snappy tooltips we are used to
from KDE4 times. Apparently this was forgotten when
porting to the new interface.
Bring back eventuallyStartAssistant private slot.

We use that extensively via QMetaObject::invokeMethod.
Remove another todo message, this looks OK to me. We don't care for multi-line edits after all.
Fix crash on shutdown.

Apparently the old-school Qt signal/slot connection was more
safe here before. The new-style connect gets executed when the
plugin is about to shutdown and then we'd crash. Now we manually
disconnect to prevent that from happening.
Don't set a minimum size on the settings dialog.

It apparently completely messes up the whole dialog and leads to
very strange behavior (it can be made as small as you want...).
Add todo on future cleanup possibility.