base-control: documentation (fix: sipayRT, gela-d)
Merge pull request #502 from bem/issues/489@v2

base-control: documentation
checkbox-group: make the block (close #427)
Merge pull request #437 from bem/issues/427@v2

checkbox-group: make the block (close #427)
base-control: remove/add tabindex when disabled mod is changed (close #509)
remove redundant code
remove tabindex only for disabled menu
dropdown block description