Move Open Graph comment inside conditional, fix indentation.

These are primarily cosmetic, resulting in less confusing HTML being generated for those who care to look.
Simplify the optional inverse navbar conditional.

Less repetition is always better than more. Also, change <nav/> to <div/> as that is standard HTML and is what the Bootstrap examples all use.

These changes are cleanups. They should have no visual or functional effect.
Cleaning up meandering indentation.
Merge pull request #42 from hlapp/cleanup-fixes

Cleanup fixes