Support Gradle incremental annotation processing

[WonderCsabo]

It would be nice to support incremental compilation, if possible.

https://docs.gradle.org/current/userguide/java_plugin.html#sec:incremental_annotation_processing

[mseroczynski]

Any updates on that? DBFlow is the only library around that still has this blocker. @agrosner

[agrosner]

fixed in develop for 5.0.0-alpha2