Upgraded 1.4 cases to 1.5.

uniformDimensionedVectorField.

Moved the snappyHexMesh tutorials to the appropriate solver directories and created links.

Note the reversal between the p and U factors for compressible flow.

	modified:   ../../../compressible/rhoPisoFoam/ras/cavity/constant/polyMesh/boundary
	modified:   ../../buoyantPisoFoam/hotRoom/constant/polyMesh/boundary
	modified:   ../../buoyantPisoFoam/hotRoom/system/controlDict
	modified:   ../../buoyantPisoFoam/hotRoom/system/fvSchemes
	deleted:    ../../buoyantPisoFoam/hotRoom/0/mut
	modified:   constant/polyMesh/boundary
	deleted:    ../../buoyantSimpleRadiationFoam/hotRadiationRoom/0/mut
	deleted:    ../../chtMultiRegionFoam/multiRegionHeater/0/mut

- change system/controlDict to use functions {..} instead of functions (..);
  * This is internally more efficient
- fixed formatting of system/controlDict functions entry

- pedantic change: use 'return 0' instead of 'return(0)' in the applications,
  since return is a C/C++ keyword, not a function.