make qoppy a proper package
Use package for main target
first, very basic test
 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
correct test
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  always return after calling
  fix parser
merge last bits of m_eval into interpret and rename interpret->m_eval
Merge branch 'master' of git://github.com/timfel/qoppy

* 'master' of git://github.com/timfel/qoppy:
  get rid of m_eval

Conflicts:
	qoppy/runtime.py
Merge branch 'master' of git://github.com/timfel/qoppy

* 'master' of git://github.com/timfel/qoppy:
  mustn't return W_Call expressions
Merge branch 'master' of git://github.com/timfel/qoppy

* 'master' of git://github.com/timfel/qoppy:
  fix translation
  add a merge point for the Jit

Conflicts:
	qoppy/runtime.py
rename qoppy.py to make pypy translator happy
remove virtualizable, does not help
env, stack, and operand_stack are linked lists
add W_EvalCall, because both operate and eval have to be flattened into the loop
tests
strings (for debugging)
change