Add some timeout checks to new BDD zipper.
Get rid of a particularly expensive sanity check.
Merge branch 'master' of github.com:sos22/SLI
Iop_I32toF64 is never going to return a pointer.
Fix some timeout bugs.
Avoid a crash if we have try to optimise a sequence like this:

Assert(!x)
Assert(!y)
Terminal

And we can reduce x || y to false but cannot so reduce either x or y
individually.
Sanify MaiMap handling a little.  This seems to make some bugs go
away, but it's not immensely clear why.
Don't crash just because building an enabling table fails.
Another special case for quickSimplify.
Fix a couple of timeout bugs.
Redo exprbdd::{load,unop,binop} so as to avoid nasty exponential
blowup with particularly involved BDD reentrancy structures.
Make sure that avail analysis works for the data argument of a store
side effect, as well as the load.
Reduce code duplication a bit.
Tidy up allocation header a little bit.
Make sure that quickSimplify recurses into subexpressions correctly.
This helps normalise expressions much further, which reduces the
number of variables in BDDs.  Given that a lot of algorithms used have
worst-case complexity O(2^n) in the number of variables, you don't
need to reduce the number by very much to get a useful win.
et another timeout fix.