Move music content to separate repo.
Removed old timer event classes
Merge branch 'develop' into soundtrack
Use the inheritence cache in all getElementStyle methods.

Reduces unnecessary object allocation.
Separate celestial events into new package
Climbing improvements
Extract celestial model into it's own class
Merge PR #1340 by @meniku - climbing improvements
Readd the old ladder (dug out of the legacy branch)
Merge PR #1337 by @flo - ui cleanup
Merge PR #1338 by @msteiger - refactor celestial / time setup
can now move away from ladder via strafing keys
Ladder is not penetratable anymore
refactorings
allow movement on both ledges, when there are two or more adjacent ledges around a corner.
Update Gradle to v2.1
Update version numbers
Dont expose internal data in Facet interfaces
Added Quadtree and Octree implementation in one.
Switched to latest version of gestalt-module.
Removed extra date/release information from version number.
Changed engine version to snapshot.
Changed core version to snapshot.