apply patch
PunchPool has to be public
update doc
formatting
Merge branch 'master' into state-handling

Conflicts:
	src/main/java/com/github/marschall/punch/ListenableTask.java
	src/main/java/com/github/marschall/punch/PunchPool.java
	src/test/java/com/github/marschall/punch/PunchTest.java