Make the method names more consistent and their semantics simpler:
hasRef and seekRef to look up a single exact reference by name and
hasRefsByPrefix and seekRefsByPrefix to look up multiple references by
name prefix.
In particular, splitting hasRef into two separate methods for its
different uses makes DfsReftableDatabase.isNameConflicting easier to
follow.
[jn: fleshed out commit message]
Change-Id: I71106068ff3ec4f7e14dd9eb6ee6b5fab8d14d0b
Signed-off-by: Minh Thai <mthai@google.com>
Signed-off-by: Jonathan Nieder <jrn@google.com>
263a8c1c06