Improved dropdown menus

Attention! Dropdown menus are now moved into document's body to prevent issues with "display: overflow" set for certain elements. Please check the new API methods of WCF.Dropdown, especially the changed API signature for registered callbacks.
Updating minified JavaScript files
Small language optimization

Fixed inconsistent usage of the name "Google Plus" (see en.xml)
Fixed obsolete/invalid schemaLocations
Merge pull request #1300 from SoftCreatR/XSD

Fixed obsolete/invalid schemaLocations
Merge pull request #1299 from SoftCreatR/consistentGPlus

Small language optimization