enhanced build.gradle
enhanced build.gradle

* fix incremental build which is destroyed by putting a timestamp to `MANIFEST.MF`
* compile parameter especially for Java 8
* package LICENSE and NOTICE file

Signed-off-by: Andreas Schmid <4cf5bc59bee9e1c44c6254b5f84e7f066bd8e5fe@aaschmid.de>

aaschmid/taskwarrior-java-client,aaschmid/taskwarrior-java-client