Created a base-class from contactAngleForce from which the
distributionContactAngleForce (for backward compatibility) and the new
temperatureDependentContactAngleForce are derived:

Description
    Temperature dependent contact angle force

    The contact angle in degrees is specified as a \c Function1 type, to
    enable the use of, e.g.  contant, polynomial, table values.

See also
    Foam::regionModels::surfaceFilmModels::contactAngleForce
    Foam::Function1Types

SourceFiles
    temperatureDependentContactAngleForce.C