BSSN/BSSN_quantities.py: epsDD should be initialized to zerorank2, not zerorank3.

BSSN/ADM_Initial_Data_Reader__BSSN_Converter.py: register_CFunction_exact_ADM_ID_function(): Fix bug in setting r,th,ph from Cartesian coordinates, when Spherical coordinate initial data are chosen.

reference_metric.py: rfm_precompute has a problem with crossed second derivatives, so replace the only function of two variables in rfm_precompute: f2_of_xx0_xx1, used in SymTP coordinates, with functions of single variables since it's separable.

SIMD.py: Add x^(-1.5) and x^(-2.5) parsing. Courtesy Thiago Assumpcao

SIMD.py: Fix behavior of x^(-1/2), such that it uses the SIMD version of 1 instead of the integer 1

Merge pull request #81 from tyndalestutz/master

Merge branch 'master' into master

(hopefully) finishing touches

added missing abstracts

quick save

Fix SIMD doctests, and run SIMD doctests at each commit.

CI: Removed testing for Python 2.7

Merge pull request #83 from stevenrbrandt/fix-simd-try2

Make the unit test work again

Fix Simd