Implement range checks for all parameter types

[ianhinder]

Cactus supports restricting the allowed range for user parameters. This should be made available to Kranc users. Currently, this is implemented for keyword parameters. There is an AllowedValues key in the parameter structure for this, but it only works for keyword parameters. It is also used for integer parameters when generating special-case code for finite differencing operators, but there is not currently any check that the user actually specified an allowed value.