Moved getters from Sounds and Rotations to GameRegistry.

This has been done as every other Class like this e.g. Blocks, Items, Environments, Biomes do not have getters. The getters for these should be in GameRegistry as they have to be registered like the above examples.
These imports should be avoided as defined in the Google Java code style: https://google-styleguide.googlecode.com/svn/trunk/javaguide.html#s3.3.1-wildcard-imports

> [ant:checkstyle] /home/travis/build/SpongePowered/SpongeAPI/src/main/java/org/spongepowered/api/GameRegistry.java:35: warning: Using the `.*` form of import should be avoided - org.spongepowered.api.entity.living.meta.*