I moved everything into the Corundum package.

I moved everything into the Corundum package to help ensure that things
that are package-visible are not accessible to plugins or other programs
and to help ensure that the main classes are kept inside a package since
referring to things statically without a package doesn't work in Java.

Signed-off-by: REALDrummer <conman.davey@gmail.com>
Merge pull request #4 from asusoda/Block

I moved everything into the Corundum package.