3.0+ Dropdown Header

Added ability to use the new class, left the old reference to
"strcasecmp($item->title, 'nav-header') " but changed the class it
outputs to "dropdown-header".

Backwards compatibility to be removed when Bootstrap 3 officially
launches.
Comments

forgot to close my comments lol
Update README.md

Added notes about some new/updated class names in Bootstrap 3
Update README.md
Merge pull request #1 from pattonwebz/dev

Dropdown menu fixed
Merge pull request #16 from pattonwebz/Bootstrap-3.0+

pattonwebz updated dropdown headers
Completely rewritten for WP 3.6 & TBS 3.0+
Merge remote-tracking branch 'origin/Bootstrap-3.0+'

Conflicts:
	wp_bootstrap_navwalker.php