Update .navbar-toggle to match other navbar elems

In place of commit #9040, fixes #8844
And sizing .navbar-toggle more like .btn elem
+ change `position:absolute` to `position:relative`
+ remove `right: 10px` in favor of `float:right`
+ change to `height: 34px`
+ remove `top:` in favor of `.navbar-vertical-align` basis new height
+ change `padding:` to match `.btn` elem