Added struct packing for auxiliary arguments
Merge pull request #131 from izaid/pack

Struct packing
Fix fftw compile error
Create design doc arrfuncs.md
Add files for arrfunc registry support
get_regfunction and set_regfunction functions
Add init/cleanup functions for the arrfunc registry
Put some basic functions in the registry
Switch the few registered functions to use multidispatch, add tests
Fix for non-windows math functions
Add a few more math functions to the registry
Simplify the math arrfuncs being created, add sanity checks

Including <math.h> includes the *f variants which didn't seem
to be there before, and the *f variants only have one overload
so don't need a static_cast
Add a tweak to multidispatch to include kind-ordered edges
Add arithmetic functions to the registry
Gcc computed coshf inconsistently, try FLOAT_EQ instead of DOUBLE_EQ
Add simple use cases arrfuncs should handle, with design implications
Add a few more functions to the arrfunc registry
Add a few more arrfunc use case examples
Start a doc describing general arrfunc-ckernel functioning

Trying to write down a design which incorporates the various
use-cases described in the arrfunc.md doc
Fleshed out most of an updated design for arrfuncs

Adds dynamic params and a few other things