repl
executable repl
prep presentation
update with slight adjustment
start an interpreter loop
use W_Call as marker
 more meaningful tests
MErgerMerge remote-tracking branch 'upstream/master'

* upstream/master:
  use W_Call as marker
  start an interpreter loop
  update with slight adjustment
  prep presentation
  executable repl
  repl

Conflicts:
	qoppy.py
	qoppy/execution_model.py
	qoppy/runtime.py