@see
- http://gradle.monochromeroad.com/docs/userguide/custom_plugins.html
- http://www.gradle.org/docs/current/userguide/custom_tasks.html
- gradle api
$ ./gradlew example
...
:example
default
$ ./gradlew example -Pgreet=test
...
:example
test
@see
$ ./gradlew example
...
:example
default
$ ./gradlew example -Pgreet=test
...
:example
test