Navbar toggle is not vertically aligned (3.0.0-wip) with custom navbar height

When using navbar heights higher that default, the navbar-toggle button is not centered.

Fiddle demonstrating this issue (compiled with `@navbar-height: 60px;`): http://jsfiddle.net/tagliala/mRVMe/2/


Another fiddle with the proposed fix: http://jsfiddle.net/tagliala/mRVMe/3/
fix #8584: add readme callout for npm and node
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip
Merge branch '3.0.0-wip' of https://github.com/tagliala/bootstrap into tagliala-3.0.0-wip
make on prev commits