Adding model to models-list at specific index implemented
Works correct with index === 0
Added "s" in field type.
Merge pull request #1 from verkholantsev/sul.doc.fix

Added "s" in field type.
Separate method addByIndex for models-list field
Merge branch 'master' of github.com:verkholantsev/bem-mvc
Merge pull request #79 from verkholantsev/master

add ability to add model to models-list at specific index