mon: MonmapMonitor: support 'mon getmap [epoch]'

Fixes: #6683

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
mon: OSDMonitor: proper error msg on invalid epoch on 'osd getmap/dump'

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
autoconf: check for res_nquery explicitly

Creates a test that checks explicitly for res_nquery, which can be a
macro in resolv.h. Defines RESOLV_LIBS that contains any libraries that
need to be linked against.

Notes from later fix:

Based on the 2013-09-30 version of wip-port.  On FreeBSD, one must
include netinet/in.h to get the definitions for stuff in resolv.h.
Also, resolv.h's functions are part of libc instead of libresolv.

Signed-off-by: Alan Somers <asomers@gmail.com>
Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
trace: remove unused header

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
Merge pull request #836 from ceph/port/unused-headers

trace: remove unused header
Merge pull request #789 from ceph/wip-6683

mon: MonmapMonitor: support 'mon getmap [epoch]'

Reviewed-by: Sage Weil <sage@inktank.com>
Merge pull request #823 from ceph/port/detect-libresolv

autoconf: check for res_nquery explicitly
Merge git://github.com/ceph/ceph