move a bunch of code around

hoping to make it easier to put into a library later.
also preparing to rearrange the CodeFrame stuff
move all instruction code into instruction.cpp

this will make it easier to put into a library in the future
also queued up a lot of rewrites around the CodeFrame scheduling
first pass at switching to CallNode structures

and away from CodeFrame stuff. this is in preparation for adding c calls
and io calls to the call tree, just like regular qbrt calls
another checkpoint in rewriting CodeFrame objects

move WorkerCContext to instruction.cpp
implement a few more methods in new CallNode object heirarchy
remove the CodeFrame related objects

replacing them with the CallNode related objects