plugin: sys_time: Add time syncronization diag.

Issue #156.
plugin: sys_time: Set right suffixes to uint64_t constants.

Issue #156.
mavconn #161: Move library to its own package

Also rosconsole replaced by console_bridge, so now library can be used
without ros infrastructure.
mavconn #161: Fix mavros build.
mavconn #161: Fix headers used in mavros. Add readme.
mavconn #161: Move mavconn tests.
mavconn #161: try to fix hydro build
mavconn #161: Enable rosconsole bridge.
fix build deps for gcs_bridge
Prepare minor release 0.8.1
0.8.1
REP140: update package.xml format.

Hydro don't accept this format correctly,
but after split i can update.
prepare minor release 0.8.2 for indigo
0.8.2
Prepare release 0.9.0 for indigo.

Because of technical issues i release 0.9 with uncomplete milestone.
Now hydro versions freezes at 0.8.x, so indigo must use next minor
number to give a room for git tags.

Issue #162.
0.9.0
Update installation notes for #162
Fix libmavconn deps.

Releases 0.9 and 0.8.3 ar broken because i forgot to add mavlink dep.
prepare hotfix release 0.9.1
0.9.1