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.
Adding unit test for GasRecombinationCatalyticWall