Disallow "*/maskbits" as an address pattern.

Fixes bug 7484. We've had this bug back in a8eaa79e031ee04d44 in
0.0.2pre14, when we first started allowing address masks.
Implement scheduler mechanism to track lists of channels wanting cells or writes; doesn't actually drive the cell flow from it yet
Temporarily disable scheduler_trigger as unused
Fix unused-arguments warnings
Use event_active, not 0-length timeouts. It's idempotent, too.
Uglify scheduler init logic to avoid crash on startup.

Otherwise, when we authority try to do a self-test because of
init-keys, if that self-test can't be launched for whatever reason and
so we close the channel immediately, we crash.

Yes, this a silly way for initialization to work.
Provide generic mechanism for scheduler to query writeable cells on a channel
Actually call channel_flush_some_cells() from the scheduler
Remove no-longer-used channel_tls_t functions
Add global cell/byte counters and per channel byte counters to channel.c
Make 'make check-spaces' not complain about function pointers returning size_t or double
Track total queue size per channel, with overhead estimates, and global queue total
Implement global queue size query in channel.c
Fix return values from channel_flush_some_cells() to correctly count cells directly written by channel_flush_from_first_active_circuit()
Let the new scheduler handle writes
Schedule according to a queue size heuristic
Add cmux support for inter-cmux comparisons
Add inter-cmux comparison support to circuitmux_ewma.c
Sort the scheduler's channel list by cmux comparisons
Fix compiler warning