- this provides a better typesafe means of locating predefined cell
models than relying on strings. The lookup is now ptr() or ref()
directly. The lookup functions behave like on-demand singletons when
loading "etc/cellModels".
Functionality is now located entirely in cellModel but a forwarding
version of cellModeller is provided for API (but not ABI) compatibility
with older existing user code.
STYLE: use constexpr for cellMatcher constants
Moved file path handling to regIOobject and made it type specific so
now every object can have its own rules. Examples:
- faceZones are now processor local (and don't search up anymore)
- timeStampMaster is now no longer hardcoded inside IOdictionary
(e.g. uniformDimensionedFields support it as well)
- the distributedTriSurfaceMesh is properly processor-local; no need
for fileModificationChecking manipulation.
