Accomplishes a few things.

• Updates the Checkstyle version we were using.
• Merges some of the upstream checkstyle file changes from checkstyle/google
• Fixes a lot of spelling errors
• Adds some missing Javadocs
• Consolidates all of the package info files to one format and adds some missing ones
• Fixes the Javadocs errors on build
• Removes unused imports
• Fixes some minor issues here and there, mostly all relating to formatting

We are now closer to following our own style guide. Not completely there yet but we'll get there.

I tested the changes to a basic extent make sure I didn't break something accidentally. Seemed to go fine.

I split most of the changes into coherent commits, but one or the two commits didn't get commited fully so some of their changes are in the next commit, and other commits just have general fixes.

Eventually I will come back and cleanup remaining Javadocs even more and add some to places where they are quire needed, such as some properties and the listings of some catalog types.