Make sure transition setting is passed as an integer to responsive-nav.js

The transition option is not explicitly passed as an integer to the responsiveNav function. In the latest version, a default timeout is added to this transition, resulting in a string concationation instead of an add of this two numbers. This results in a very high timeout for the animations.

Example: Setting in Drupal is 400ms, the value "400" gets passed to responsiveNav. In responsiveNav there is an opt.timeout + 300 which results in "400" + 300, which is 400300 instead of the expected 700ms.
Doing a parseInt in responsive_navigation.js will fix this issue.