Added custom toggle element option
Added unchecked menu items

* selector unchecked-partial
* selector unchecked
Removed partial as superfluous
Minor code review
Added field type number, code cleanup
Added field type number to LESS
Hiding arrows in number field
Added info on short method to slider doc
Added unchecked to menu doc
Fix menu doc class values
Merge pull request #477 from greensolid/develop

Enhancements to dropdown, menu, slider and forms