Incremental processor

[naixx]

Any plans for implementing incremental compilation support?
Right now it seems there are no obstacles for this. The processor can define isolating in most cases or aggregating (if there is @ActivityStarterConfig defined somewhere within the project) dynamically using the latest Gradle support.

According to this processor satisfies all the rules.

I'm just not sure if it is possible to make a processor dynamic based on the presence of an annotation. Why is it important - isolating processors are much faster. Probably a compiler flag (by a user) can signal that a user doesn't use config.