Preliminary stable release of new c++ UtahLSM

This is the preliminary beta release of the new c++ version of the UtahLSM. The model is generally stable.

Outstanding work:

• improve numerical stability
• add more advanced physics, such as root zone and runoff
• restructure API and make model handle initialization
• create interface to allow inclusion in fortran code

UtahLSM v1.0

This is the initial version of Utah LSM, which was written in 2012 and is described in Shingleton (2010).