Clean up crufty classes

[jhakala]

We have three classes that are more-or-less useless at the moment:

• HCALSetParameterHandler: this should be eliminated, since almost all the handler classes do some separate setting of parameters without going through the HCALSetParameterHandler
• HCALMonitorHandler: this does nothing now, so we should figure out if we ever want to use it, or get rid of it
• HCALErrorHandler: we could revive this class to take over error condition handling, e.g. the goToError method, but it may need a more thorough rewrite