Try to recover after deleting opened files on NFS

Try to recover after deleting opened files on NFS

Fixes various LocalRepositoryTestCase based tests, which were failing if
executed on NFS mount, see Bug 440182. The current workaround doesn't
really checks for NFS (have no idea how to do this in Java) but allows
tests running on "/home" to run "delete" cleanup twice (second "delete"
round deletes unexpected nfs zombie files). The assumption is that this
workaround should at least help *nix users with their NFS mounted home
directories.

Ideally the tests should be fixed to properly cleanup opened .pack file
handles, but I've spent one day hunting the root cause on one single
test without success, due the asynchronous nature of the resources
creation/cleanup.

Bug: 440182
Change-Id: I5e879daed954aa35de197d8e1ea43c9fbccca7d4
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>