Compatibility with libMesh interior_rate API
More mass_residual, jacobians updates

This adds further corrections for the mass_residual sign convention
change in libMesh and for the "TimeSolvers won't hold your hand and
ensure elem_solution_derivative isn't fractional" change.  The number
of regressions is decreasing but still nonzero...
Adding missing fixed_deriv multipliers
Fix compatibility with new templating

this->C++ this->requires this->us this->to this->preface this->any
this->member this->names this->so this->the this->compiler this->can
this->figure this->out this->what this->is this->going this->on
this->even this->in this->the this->presence this->of this->templates.

this->this this->is this->possibly this->the this->most this->annoying
this->part this->of this->C++.
Merge pull request #159 from grinsfem/fem_system_rates

Fem system rates
Add method to viscosity for evaluating at a point.

This is introducing a bunch of warnings about ambiguity of types, see
http://stackoverflow.com/questions/3519282/why-is-this-ambiguity-here
Need to get rid of the old interface that's being used in
LowMachNavierStokes. Was hoping to avoid recomputing temperature -
need to think about the right API for that.
Add postprocessing computation of viscosity

Still need to register the variable before it will be output.
Register viscosity for postprocessing.

Viscosity should be plottable now.
Need to actually set the bloody value.
Don't have default value for time.

This was causing warnings in opt mode, but causing *errors* in dbg
mode. We can pass time anyway from the context, so it's not a big
deal. We can update the API later.
Need to *not* do this initialization
Add API to conductivities for postprocessing/visualization
Compute k for postprocessing

It is not enabled yet.
Register k for postprocessing

This should enabled visualization of conductivity postprocessing.
Merge pull request #176 from pbauman/mu-k-plotting

Viscosity and conductivity visualization
Merge branch '0.5.0-release'
Cannot "initialize" value in the postprocessing computation

See discussion in #175.
Merge pull request #177 from pbauman/vis-value-fixes

Cannot "initialize" value in the postprocessing computation
Merge branch '0.5.0-release'
Created a Spalart Allmaras turbulence physics, and a turbulence variables and FE variables class