More massive changes. Got rid of frames (but left many commented-out
bits in for now). Also reimplemented rendering to work with an
active_entity_area instead of a frame and to use the chunk cache instead
of frame data. Also redid chunk compilation, although currently chunk
approximations will not be compiled (this is the big TODO after I get
this code debugged and running). This revision also introduced witheach
iterators for lists, queues, and maps, which give the iterating function
an extra void * argument. This should drastically cut the number of
separate iterator functions that have to be authored.

-Peter Mawhorter
Debugged all compile errors in the massive swath of changes that I made
over the last few commits. Unit tests pass, but haven't tried running it
yet.

-Peter Mawhorter