radiationModels: Relocation, namespace changes, and fixed Qdot access

The radiation modelling library has been moved out of
thermophysicalProperties into the top-level source directory. Radiation
is a process, not a property, and belongs alongside turbulence,
combustion, etc...

The namespaces used within the radiation library have been made
consistent with the rest of the code. Selectable sub-models are in
namespaces named after their base classes. Some models have been
renamed remove the base type from the suffix, as this is unnecessary.
These renames are:

    Old name:                       New name:

    binaryAbsorptionEmission        binary
    cloudAbsorptionEmission         cloud
    constantAbsorptionEmission      constant
    greyMeanAbsorptionEmission      greyMean/greyMeanCombustion
    greyMeanSolidAbsorptionEmission greyMeanSolid
    wideBandAbsorptionEmission      wideBand/wideBandCombustion

    cloudScatter                    cloud
    constantScatter                 constant

    mixtureFractionSoot             mixtureFraction

Some absorption-emission models have been split into versions which do
and don't use the heat release rate. The version that does has been
given the post-fix "Combustion" and has been moved into the
combustionModels library. This removes the dependence on a registered
Qdot field, and makes the models compatible with the recent removal of
that field from the combustion solvers.

applications/test/Function1/Make/options

@@ -1,7 +1,7 @@
 EXE_INC = \
     -DFULLDEBUG -g -O0 \
     -I$(LIB_SRC)/lagrangian/intermediate/lnInclude \
-    -I$(LIB_SRC)/thermophysicalModels/radiation/lnInclude \
+    -I$(LIB_SRC)/radiationModels/lnInclude \
     -I$(LIB_SRC)/finiteVolume/lnInclude \
     -I$(LIB_SRC)/meshTools/lnInclude