Remove the --schema option from Traffic Manager

There's a "-schema" option for traffic_manager, which is only partially implemented (and we have no default scheme file to provide for it). From what I can surmise, the intent was to allow for a schema based validation of records.config.

Now, I suspect this -schema option was done prior to RecordsConfig.cc refactoring. As such, I feel it's unnecessary, since RecordsConfig supports validation "rules" for each configuration.

Finally, since this feature has no usable configurations or features, I suggest eliminating it for v4.2.0, but I could be convinced to move it out for v5.0.x.