UNREAL-73 Updated changelog with other changes - copyright, addition …

…of an empty class

Merge pull request #16 from leapmotion/feat-add-changelog-and-update-…

…plugin-submodule-pointer

Feat add changelog and update plugin submodule pointer

update to 4.23

fix automap at init for examples

update for 4.22

update for 4.21

update for 4.20

remove old redirectors

add sdk notice