Reformat source code with IntelliJ IDEA preset

Some of this may be slightly off but it's better than it was
Merge pull request #152 from Kobata/style-reformat

Reformat source code with IntelliJ IDEA preset
Update README.md, add CONTRIBUTING.md

Signed-off-by: Steven Downer <grinch@outlook.com>
Add modifed google style checkstyle.xml

Commented-out things are features that require unreleased versions
of checkstyle.
Github's urls are case-sensitive
Fix documentation of PluginManager.getPlugin

It is looking up by ID, not name
Add IntelliJ formatting setting xml file
Added subscription to VoxelEvent
add support for FML's dependency format to @Plugin
move loggers, etc. for plugins over to a PreInitializationEvent
get rid of global logger in game
update example plugin for new logger changes
Add Guava 16 as a dependency.
Add JUnit, Hamcrest-library, and Mockito as test dependencies.
Add preliminary command interfaces.
Fix an incorrect assertion that getCause() won't return null.
Merge branch 'master' of git://github.com/SpongePowered/SpongeAPI into config

Conflicts:
	src/main/java/org/spongepowered/api/plugin/PluginContainer.java
Move package to configuration

Signed-off-by: Matthew Messinger <mattmess1221@gmail.com>
Remove name from element
Update for changes while doing Impl.
Add Nullable and Nonnull annotation in places.