Early matrix/vector support

a reimplemetation of the numpy matrix class, with:
 - slightly different printing
 - convenient element-wise functions
 - overloaded <= for constraint generation
adding utils stuff back in
making it work with tests
swapping out lambdas
Merge branch 'tests' into matrices
switched to arrays
switched to using arrays!
Merge branch 'nomials' into matrices

Conflicts:
	gpkit/__init__.py
	gpkit/utils.py
Merge branch 'master' of https://github.com/appliedopt/gpkit into matrices
Merge branch 'matrices' of https://github.com/bqpd/gpkit into bqpg-matrices
make imports absolute