Changed unit tests to not use box2d.
* Added (very basic) mocks for PhysicsBody, PhysicsShapeFactory, PhysicsShape and PhysicsWorld
* Updated GameImpl.java to not always create a physics world.
* Changed the ant test target to run the all tests.
Merge branch 'development' into testNoBox2d

Conflicts:
	build.xml
Fixes to build.properties and build.xml.
* Removed an unused property from build.properties.
* Set haltonfailure to true for the junit target, or the build would pass even if the tests failed.
Changed the .classpath to use local junit .jar instead of eclipse provided one.
Revert "Changed unit tests to not use box2d."

This reverts commit b09b8355f5396867eb4a478e04c32ddc7c06547c.

Fixed Conflicts:
	build.xml
Fixed build dependency on libgdx natives.
Added a static Common class for tests to load required resources.
Modified all tests to invoke Common.loadEssentials before running.
Merge branch 'development' into testNoBox2d

Conflicts:
	Bullet-Inferno-test/src/se/dat255/bulletinferno/model/TimerImplTest.java
Merge pull request #3 from Jokab/testNoBox2d

Tests can now be run outside of eclipse as the box2d is correctly included in the build.xml file.