a bunch of cleaning to get wayward unit tests passing on windows. not there yet.

a bunch of cleaning to get wayward unit tests passing on windows.  not there yet.
also a nice change in tree, to support the 40,000 deep symbol tree test that was barfing.
this was totally due to having a recursive destructor with a crazy deep tree; we blew out the stack on windows,
which we never even noticed on linux.  replacement algorithm does an iterative spider instead of beautiful
recursion, but it also handles arbitrarily large trees with no additional stack frames.