generalized lindblad_operator to optionally take two operators as input
remove function that adds np. to function names because it does not work (broken for np.arctan)
wip: use multiline code segments instead of many lines
distinguish between ndarrays of Qobjs and a full ndarray matrix for basis transform
further code cleanup in codegen
use four spaces instead of broken mix of tab argument and explicit tabs
fixed another tab issue
allow specifying a transformation matrix as Qobj operator
Merge pull request #153 from jrjohansson/generalized-lindblad-operator

Generalized lindblad operator
by default use math functions from libc.math in cython code
default to numpy math functions, keep explicit import of libc.math
Merge pull request #154 from jrjohansson/cython-jit-imports

by default use math functions from libc.math in cython code
Added functions for bell states and singlet/triplet states
Fixed bug in triplet_states()
Fixed bug in triplet_states()
resolved merge conflict
Removed states.py from qip module
Removed import qutip.qip.states from __init__.py
Replaced reg_str2array implementation with ket()
Removed utils module from qip