Zorba_SerializerOptions should not silently ignore invalid parameter values

[Chris Hillery]

Zorba_SerializerOptions::SetSerializerOption() converts string parameter/value pairs to enumerated values. It perforce checks for all possible valid parameter names, and all valid values for each parameter. However, it silently ignores any invalid parameter names or values. This method is tied directly to the Zorba's -z (--serialization-parameter) command-line options, which means that any typos on the command line silently do nothing. eg,

  zorba -q '1' -z undeclare-prefixes=foo

reports no error; nor does

  zorba -q '1' -z indeclare-prefixes=yes