Allow parent of dropdown be a real link

[auipga]

When changing the behaviour of the menu (eg. open on hover), it should be allowed for the parent of a dropdown to have a URI instead of forcing to href="#"

Example: (--> About) http://vadikom.github.io/smartmenus/src/demo/index.html

[phiamo]

@auipga how does this behave if you dont set an uri ?

[auipga]

@phiamo if no URI is set, it uses the original # as fallback

https://github.com/phiamo/MopaBootstrapBundle/issues/1035 is not connected with my issue but should also be applied (uri = javascript:;) as this change is a good idea.