add stackprof profiling

not sure how useful it is yet, but worth looking at as we make changes
here
switch to Lua script for update operation

no massive CPU savings in casual profiling, but should cut outgoing
bandwidth in half at least, so that’s something? advantages should be
compounded over time.

closes #5
comment cleanup

trying to make things a little more readable for other dev before any
refactoring
Merge branch 'perf'