begin a module for symbolic nth derivatives of univariate functions
rename dumbderiv to nthderiv, incorporate the module into the directory structure, use decorators to describe the extended functions more intelligently
more testing and bug fixing for the nthderiv branch
extend test coverage to more functions
Merge pull request #27 from argriffing/master

fail less silently in prod()
Merge branch 'master' of git://github.com/b45ch1/algopy into dumbderiv
purge algorithms.py of much copypasta
add special function psi and remove more copypasta from algorithms.py
add more carefulness regarding missing or non-development versions of optional packages
found another scipy.special.erfi
use a more complicated algorithm for erf -- maybe it is technically O(d^2) instead of O(d^3)
move more code from utpm.py into algorithms.py in a way that uses specialized code for the 'zeroth derivative' case
implemented and partially tested an O(d^2) algorithm for truncated Taylor series of solutions of somewhat general ODEs
test the O(d^2) DawsonF differentiation based on its ODE
add tests for ODE versions of log1p and expm1
implement O(d^2) dawson F function, and de-clutter test_utpm.py by moving scalar function identities to a separate module
fixed bugs in pow(x, r) when r is a positive integer and added __truediv__ and __rtruediv__ to the class UTPM
skip some tests that are failing after reverting to non-development scipy
fix merge conflicts for the pow bugfixes
fixed another merge issue and made sure the tests passed