PIUtil is more convenient if it returned objects

Currently it returns primitive longs, but I would prefer it if it returned Longs.
1.1.52
forgot to add the test changes last time... sorry
Merge remote-tracking branch 'origin/master' into hr-pi-util-return-objects

Conflicts:
	pom.xml
bump to 1.1.55
bump version to 1.1.57
Merge pull request #74 from nla/hr-pi-util-return-objects

PIUtil is more convenient if it returned objects