vault.root property - storage root

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jollamobile.com>
is_invalid error reporting is more verbose

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jollamobile.com>
[rpm] added missing dependency on git

TODO: it should depend on git-core in future when git package will be
updated to one does not depend on perl

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jollamobile.com>