Yet more BDD quickSimplify special cases.
Whoops: can't put a std::map<> in a StateMachine, because the latter
is GC'd and the former isn't GC-safe.  Just use a vector of pairs instead.
More timeout checks.
Fix silly IRExpr parser bug.
Fix a couple of places now that cfg_roots is a vector rather than a map.
Fix silly bug in CEP parser.
Filter out a whole bunch more operations which can't be correctly
handled by the crash enforcement mechanism.
Various CEP optimisations mean that we can sometimes end up with stash
points which can't be reached from any roots.  Filter them out.
Make it a bit more obvious when a CED can be safely discarded.
Lots of extra timeout handling.
Whoops: unswap arguments to start_low_level_thread.
Merge github.com:sos22/SLI
I pretty much always run with DATABASE_RIP_DEPTH 1, so make that the
default.
Similarly, I pretty much always run with the induction rull off, so
make that the default.