Changed the border-color of .navbar-form to @navbar-default-border

BS3 commits: 515e11da32a16c60c8b607e08f5ca3020b29e7ba
Removed unneeded 'accordion-toggle' class from collapse examples

BS3 commits: 21486ffad80913bdec8d087be50c39359721e4a9
Variablize nav pill border radius

BS3 commits: f2750dd6bcb27648977d2c2de2931d945c5492a8