ipc: remove entry from sendwait_hash on send timeout

(red face)
testbench: reassign forkserv's exit label
ipc: fix read xfer fault address

Now it matches the position where space_memcpy_from() operates, which is at
least as-correct-as.
mapdb: add simple postcondition to mapdb_add_map()

That's to say, there could be others -- and this one could be stricter.
fix L4_Never in L4_ReplyWait_Timeout()

Replying never waits.
testbench: add delay function to string_suite, meta case, delay test

Also some debug crud in ipc.c .

This cset seems to work as far as the delay test and such are concerned.
Though it adds no tests, it's useful in demonstrating that those things the
tests require to pass are supported in the microkernel.
testbench: rewrite test ID generation

It still uses a similar algorithm, and produces similar outputs, but now the
unique identifier is appended to the end of the space-tcase-test prefix
triple. This may make test IDs slightly longer.

I have no idea why the previous one didn't work.
add options to the on/off tracing module

Only one option so far: printing of read_global_timer()'s value as a prefix.
ipc: rewrite abort_thread_ipc()

Being untested, it was quite wack. It also doesn't need to handle states other
than TS_SEND_WAIT and TS_STOPPED, so asserts were modified accordingly.

This changeset adds a callsite from thread_destroy(), which was previously
missing.
change SystemClock to indicate time in µs, not ms

This causes cascading fail in the testbench. The following changesets will fix
that.
testbench: calibrate delay loop according to KIP ClockInfo
testbench: fix ms-vs-µs breakage in sched_suite.c

There's plenty of it.