First attempt at implementing configurable monitor subscriptions using p2p communications instead of shared bus.
More work on monitor subscriptions: added /subscribe message handler with granular control over items of interest (device, inputs, outputs, links, connections). Changed device sync ping to include name, also use for response to /who message. Detailed device metadata available through subscription.
Switched monitors to subscription model.
Added subscription-autorenew functionality to monitor.
Remove monitor request functions.
Store mesh admin port of remote devices in router/receiver datastructure, use for p2p admin responses.
Python: switch to monitor subscription model.
Properly handle changing flags for existing subscriptions.
Send /connectTo message p2p since link src is known. Test programs using monitors need to wait for link to be established before connecting.
Return correct number of file descriptors.
Merge branch 'admin2' into admin2-simplify
Remove admin functions related to monitor queries.
Fixed bugs in signal removal from db.
Monitor: remove auto-renewing subscription when device logs out.
Merge branch 'admin2' into admin2-simplify

Conflicts:
	src/monitor.c
Merge branch 'master' into admin2
Add device info handler to mesh handler list.
Python: Add defaults to subscription arguments.
Test programs: wait for link before sending /connect messages.
Removed magic numbers in monitor.c; allow admin to resume subscription without resending data if reported device version number matches.