Renamed turbulenceProperties -> momentumTransport

Following the generalisation of the TurbulenceModels library to support
non-Newtonian laminar flow including visco-elasticity and extensible to other
form of non-Newtonian behaviour the name TurbulenceModels is misleading and does
not properly represent how general the OpenFOAM solvers now are.  The
TurbulenceModels now provides an interface to momentum transport modelling in
general and the plan is to rename it MomentumTransportModels and in preparation
for this the turbulenceProperties dictionary has been renamed momentumTransport
to properly reflect its new more general purpose.

The old turbulenceProperties name is supported for backward-compatibility.

tutorials/IO/fileHandler/constant/momentumTransport

@@ -11,7 +11,7 @@ FoamFile
     format      ascii;
     class       dictionary;
     location    "constant";
-    object      turbulenceProperties;
+    object      momentumTransport;
 }
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //