XML deserialize checks for unnecessary stream operators

[chaosct]

In order to deserialize an ofParameter, ofParameter::isSerializable() must be true. This method checks both for serializable flag and existence of stream operators (<<, >>).

However when deserializing an ofParameter, only ofParameter::fromString() is used. I use to implement fromString() for my custom ofParameter's in OF < 0.9.0, but now a dummy implementation of the stream operators must be defined to allow deserialization, which is kind of dangerous (who knows if other parts of ofParameter end using stream operators for something).

I suspect this happens also on serialization.

[arturoc]

serializable is an opt out flag for serialization, it doesn't mean that the parameter or the type 'can' be serialized but if it 'should'

then there's the check to see if a type can be serialized by using the stream operator with a stream which i think is not ambiguous (the underlying type still can implement the stream operator with other types).

we implement the stream operators across all types in OF that we want to be able to be serialized and not any form of method that way those types can be directly sent to a text file...