Switch to using @label for all call methods
Mark the result handler for a impersonated procedures as non-loops
Remove redundant mark_non_loop call
Oops
Add nucleic2 which is problematic for branches.
fix off by one error in the (so far unused) depth_and_size
simplify the env pruning code

get rid of the -1 special case and just always use the precise number of
envs to remove.
a test for remove_num_envs
more aggressive pruning

also prune the environment in a Let when some of the rhs expressions
don't need the full enclosing environment.
fix translation
Merge branch 'master' into reconstruct-callgraph

Conflicts:
	pycket/base.py