Rename module zip to properly use vert.x module naming scheme.
Remove credentials not in use

* Can't find anywhere where these system properties are in use.
* If needed for specific environments, they should probably be
specified via a local properties file.
Enable incremental compilation.
Name the ZIP file correctly using the classifier
Add missing metadata for the Vert.x Module Registry
Merge remote-tracking branch 'official/master' into complete-api

Conflicts:
	gradle/vertx.gradle

Merged by copy of newest Gradle template + Scala fixes