Add a new option called backToNormal

[mlbd]

Default desktop menu has own style and sometime has also own unique dropdown effect for dropdown menu but slimmenu create little bit issue here when some one came back from mobile menu. it's true it's not happen in real use but for checking simulator it's display odd. So, I recommend a option for this to if someone want to avoid this one they can with this change value this option.

if backToNormal has been set to true then slimmenu will =>

• Remove has-submenu when slimmenu back to normal
• Remove completly .sub-toggle when slimmenu back to normal
• Display dropdown ul when slimmenu back to normal
• Remove extra js slide effect when slimmenu back to normal from slimmenu