vary 1.1

• New create keywords with deeper meaning (#6).
  • body becomes parent.
  • htmlbody becomes insert.
  • mod becomes modifier
  • custom stays unaltered.
• New creation mode append which appends a class (#7).
• Default creation mode is now modifier but can be set using $vary-default-create (#5 and #8).
• Creation mode keyword validation is now working. If you use a keyword that is not an available vary will throw an error.