remove hard coded literals and namespace

This commit includes the following changes:
- new header file for physical constants
- new structure for global model parameters
- new input file to allow for runtime definition of model parameters
- new initialization functions for options, global parameters, and model parameters
- removal of most, but not all, hard coded literals.
- new physics.c file in vic_run/src to handle frequently used physical computations
- new shared print library
- new global parameter options for blowing snow
- removal of model parameters from global parameter file

Uncrustify was run at the end of the changes.

The following commit will address a memory error in the model.