Merge pull request #1 from bis12/master

Add tests.
Merge branch 'master' of https://github.com/bis12/eecs345-interpreter

* 'master' of https://github.com/bis12/eecs345-interpreter:
  Add count of tests
Fix test 19
Fix test 15
Fix test 16
Fix test 15 for real
Fix test 17
Fix this #t/#f garbage, and also test 18
Fix test 2
Fix tests 21 and 23 simultaneously

http://ih1.redbubble.net/image.11907026.4950/flat,550x550,075,f.jpg
Fix test 22
Fix test 9
Tweak some things for binary operands
Add two more tests for things that were bugging me
Add some tests for basic part 2 functionality
Create the new environment, it's like a parfait

...it has layers[1]

Each layer looks something like
'((x y) (10 20))

Combined, they look something like
'(
  ((x y) (10 20))
  ((x z) (5 20))
)

We traverse layers of the environment starting with the first, so x will
have the value 10. Also if you call (update-environment x 20 env) with
that environment, the first instance of x will be changed.

[1]: http://instantrimshot.com/
Merge branch 'new_environment'

* new_environment:
  Create the new environment, it's like a parfait
Update tests to be not-broken
Add clean for resetting test results
Add call/cc for return