Revert "Make Game an abstract singleton"

This reverts commit f5554865759bc4227ee5f1a56d5f5932aae15698.
Added ability to load and unload chunks.
Remove unecessary Optional from provideUnchecked in ServiceManager
Fix a multitude of Javadoc formatting errors.

For how I did this see https://gist.github.com/gratimax/47dffe6b764ac5757e3b.
Begin working on text API
Make Title API immutable
Add Translation API base
class actions
Add type parameter to Message so it can be also used for translated messags
minor changes to message
Add specific message types
Fix raw type warnings and add Iterable to Message
fix some formatting, compile stuff
Fix Selector message and Actions
fix up textformat, add more message builders
Replace action classes by interfaces again, add to builder
Improve text style API
Split colors and styles, fix some smaller mistakes.
Fix up some classes, clean up builder
Add message factory, clean up builder a little bit more
Reformat code to match Sponge's code style