Start some nav and dropdown cleanup

* Remove border-radii on top of tab dropdown menus
* Remove the .dropdown and .dropup styles and instead place  on all
* Use  on dropdown carets intead of separately applying margin with a top alignment
* Some other misc cleanup
Restore commented out dropdown styles, get open dropdown state working again
Consolidate active dropdown toggle styles and comment out the rest
fix broke example
run make on last commit
Less specific dropdown styles, change up navbar dropdown styles