ENH: add new computation module and toplevel eval function
ENH/TST: add new instance testing functions and their tests
TST: add randbool function
BUG: prevent certain index types from joining with DatetimeIndex
TST/ENH: add 2d bare numpy array and nan support
DOC: add some comments about recursion
CLN: clean up add moar better comments
ENH: add modulus support
TST: add failing modulus tests