changed is_dropdown evaluation

is_dropdown can evaluate to true even if max_depth is 0. This is the WordPress default and implies that dropdowns are enabled.
Added missing collapse class.

The collapsed navbar does not increase height to accomodate dropdowns without it.
Don't warn about unwritable htaccess if that option is disabled
Merge pull request #731 from tomdxw/feature/htaccess-warning

Don't warn about unwritable htaccess if that option is disabled
Merge pull request #730 from Foxaii/master

Added missing collapse class.
Update roots.pot
Spacing adjustments
Merge pull request #727 from amsross/master

is_dropdown can evaluate to true even if depth is not specified in wp_nav_menu() arguments
Update nl_NL.po
Remove tabs that were added during contributions
Update CHANGELOG
Updated the Dutch translation
Merge pull request #739 from royduin/master

Update Dutch translation
updates