Move clone logic away from GitCloneWizard to CloneOperation
Clone logic was unnaturally splitted between GitCloneWizard and
CloneOperation classes. Now, repository initialization part is moved
to CloneOperation, so there is cleaner separation of responsibilties.
Failure handling is also improved, incompletely cloned repository
directory is removed before reporting problem to user.
Directory creation is problematic issue because of potential errors,
so it's keeped in GitCloneWizard.
Signed-off-by: Marek Zawirski <marek.zawirski@gmail.com>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>