Added some javadoc to some of the more frequently used engine classes
Update FPS display only twice per second
Updated javadoc (UpdateSubscriberSystem and In annotation)
Update UpdateSubscriberSystem.java

Whoops, forgot to remove this
Merge PR #1357 by @msteiger - better debug display
Merge PR #1353 by @LinusVanElswijk - javadoc
Minor nonfunctional tweaks
- adjust version number - next stable would be 0.45.0 so current snapshot should be 0.44.1
- change default resolution repo to a virtual repo excluding a couple test repos
- allow user to override default resolution repo (separately from the Artifactory specific one)
- fix copy paste fun in PMD config
- adjust gradle.properties template