fixes 9642: open dropdown nav items get proper styling

BS3 commit ed4316d9b28e532d0bdbe3b5ddd23006ea7f7f9b
fixed navbar static top borders

BS3 commit e5f38207e0f8a356728e78f91a83b945934fd71d
switch to margin on navbar-nav to avoid stacking negative space reported

BS3 commit c13772d5f7584a83476a12fec379d8424ea312d1
docs cleanup on naming to fix 9710

BS3 commit 551c561ee2471681c5c7536c2cfe81d15f180cf7
finish up second pass through docs nav, headings, organization, naming, etc (another run through at 9710)

BS3 commit 3c880e681d49ade20f1b9fcbfb573172d24b3b89
Justified nav now responsive; example updated accordingly (fixes 9708)

BS3 commit e6f185acad5741fcbe0b3305e0660e5e6ea4f41c
increase spacing on homepage links and social buttons (fixes 9706)

BS3 commit d2e2ec0985d030fb230e0b8f133d5d97e453ac60