include filter when restoring does not work for for absolute paths

[fd0]

Create a directory:

$ mkdir -p work/testdir1
$ mkdir -p work/testdir2
$ mkdir -p work/testdir1/work/testdir2
$ echo 1 > work/testdir1/file1
$ echo 2 > work/testdir2/file2
$ echo 3 > work/testdir1/work/testdir2/file3

Backup that:

$ restic backup work
scan [/home/fd0/tmp/work]
scanned 3 directories, 2 files in 0:00
[0:00] 50.00%  0B/s  2B / 4B  0 / 5 items  0 errors  ETA 0:00
duration: 0:00, 0.00MiB/s
snapshot 2ca33cbd saved

$ restic ls 2c
snapshot of [/home/fd0/tmp/work] at 2015-12-14 20:52:45.407130972 +0100 CET:
work
work/testdir1
work/testdir1/file1
work/testdir2
work/testdir2/file2

Restore with an include filter with an absolute pattern:

$ restic restore --target restore --include '/work/testdir2' 2c
restoring <Snapshot of [/home/fd0/tmp/work] at 2015-12-14 20:52:45.407130972 +0100 CET> to restore

This did not restore anything:

$ ls -al restore
ls: cannot access restore: No such file or directory

Observed behavior: Restic restores nothing at all.

Expected behavior: Restic should have restored work/testdir2, but not work/testdir1/work/testdir2.