configuration parsing: give better error for missing =

A ceph.conf line with "key" and no "= value" currently shows
"unexpected character while parsing putative key value,
at char N line M".  There's no reason it can't be clearer.

Fixes: #4229
Signed-off-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
osd: an interval can't go readwrite if its acting is empty

Let's not forget that min_size can be zero.

Fixes: #4159
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 4277265d99647c9fe950ba627e5d86234cfd70a9)
qa/run_xfstests.sh: use $TESTDIR instead of /tmp/cephtest

Signed-off-by: Sage Weil <sage@inktank.com>
mds: reencode MDSMap in MMDSMap if MDSENC feature is not present

In some cases the MMDSMap message from mon -> client passes from leader ->
peon -> client, and the leader doesn't encode with the correct feature
bits.  As with MMOSDMap, we reencode the nested MDSMap based on the
features if relevant bits are not present.

We forgot to include this with the mds encoding changes.

Signed-off-by: Sage Weil <sage@inktank.com>
Merge remote-tracking branch 'gh/next'