Added a setting for navbar breakpoint in defaults
Added check in openDropdown to see if dropdown is a descendant of .navbar-collapse and window width is less than the navbar breakpoint

changed from tabs to 4 spaces

Instead of having a variable for nav breakpoint we now check if .navbar-toggle is visible.
We also have added the check to the close on mouseout, so the menu doesn't close when we hover outside the submenu.
Made a function isCollapsed so we can have our logic in one place.

Was: if ( isCollapsed ){ return; }
Now: if ( isCollapsed() ){ return; }