Not converting to template class just yet, because we lose the ability to meaningfully compare the code using the reccmp tool. My plan is to get the functions as close as possible to a match, then change over at the final step.
* Tried a "Find" method to reduce repeated code between MxAtomId::Destroy and TreeAdd functions
* Renamed the "Successor" function
* There is a destructor for the RB tree. I started on one of the companion functions but it is unfinished here.
* I think the left/right rotates are correct now. Eventually I will rename the members from m_child0/m_child1 to right/left but that ought to be its own commit.
* MxAtomId operator= match
* Added some more comments as I try to work all this stuff out.
