Starting work on refactoring of CataltyicWall.

Introducing (not yet finished) base class from which various
types of catatlytic wall boundary conditions (for gasses...) can
derive.
Fixed wrong class name
Necessary preamble.
This function should be pure virtual.
Need to define interface for the init function.
Need the reactant species index in the constructor
First draft of GasRecombinationCatalyticWall

This class handles the case of a catalytic wall where a gas is
recombining, e.g. N+N -> N_2. We are making an assumption that
only these species are involved in the reaction so that the product
mass fluxes can be computed as minus the reactant fluxes.
Build new catalytic wall classes.
Be able to deal with the axisymmetric case.

Since we're manually doing the addition to the residual, we
need infrastructure for CatalyticWallBase and its children
to know when to modify the element Jacobian.
GasRecombinationCatalyticWall axisymmetric handling
Enable GasRecombinationCatalyticWall

ReactingLowMachNavierStokesBCHandler now can use a
GasRecombinationCatalyticWall boundary condition. Still
needs testing, though.
Fix sign convention

Sign convention is outward unit normal, which was not previously
accounted for in the GasRecombinationCatalyticWall.
Use GasRecombinationCatalyticWall in regressions

At this point, GasRecombinationCatalyticWall should be equivalent
to the old CatalyticWall and there should be no difference in its
use in the regression tests.
Adding includes and forward declarations

Starting the process to remove now stale CatalyticWall. These
headers and forward declarations were missing.
Don't run catalytic_wall_unit anymore.
Removing CatalyticWall from bc handling

There's still some remanants in the code, but stale CatalyticWall
is now gone from the bc handler and is no longer being
instantiated. make check passing using the replacement
GasRecombinationCatalyticWall
Catalycity update and sign fix

With this refactoring, the catalycity for the wall is only a
function of the reactant gas. Each of the CatalyticWallBase
children will handle supplying both reactant and product wall
fluxes through the apply_fluxes function. Thus, no need to build
a product catalycity object anymore. Also, previously the sign was
built into the CatalycityBase object. This was a bad idea. Removed
and now the CatalyticWallBase and children will worry about who's
positive and negative.
Removing CatalyticWall class.
Install new catalytic wall .C files

So users can instantiate their own chemistry if they want to.
Removing now stale CatalyticWall tests.