Added hashCode to Quaternion

Quaternion was only overriding `equals()`, but not `hashCode()`. The methods are generated with Eclipse and slightly changed to make them shorter and keep the same behaviour of the old `equals()`.
Added function to add an asset to the AssetManager
Added function to retrieve all the assets of a give type
Rename get to getAll AssetManager
Removed function to add an asset to the AssetManager
added PolygonRegionLoader for the AssetManager from libgdx-utils
fixed NPE in PolygonRegionLoader#getDependencies(..)
made javadoc for Input#getX() and getY() more understandable since it caused confusion
*.jar files are not ignored by default

This caused gradle-wrapper.jar to not be included in the project repo thus defying the whole purpose of using gradlew.
Also needed for libraries that still have to be added manually.
Merge pull request #1648 from wmora/master

*.jar files are not ignored by default
Preliminary changes to AndroidApplicationBase propaedeutic for massive code reuse on Graphics classes
Made code reuse in methods initialize and initializeForView propaedeutic for upcoming changes
Removed isFragment method; let's use a specialized audio lifeclycle listener instead.
Unified AndroidGraphics class for activity, fragment, and daydream;
extended for live wallpaper.
Update AdvancedSettingsPanel.java
Fixes #1647
Fixed fragment lifecycle (hopefully).
Fixed wrong invocation to setPreserveEGLContextOnPause via reflection.
Various changes (mainly math related)
Merge branch 'master' of https://github.com/libgdx/libgdx into various
Merge pull request #1653 from Trurl101/patch-1

Update AdvancedSettingsPanel.java
Merge pull request #1655 from xoppa/various

Various small (mostly math) changes