Rename functions `backspaceToBeginningOfWord` to `deleteToBeginningOfWord` and
`backspaceToBeginningOfLine to `deleteToBeginningOfLine`.
Rename commands `editor:backspace-to-beginning-of-word` to
`delete-to-beginning-of-word` and `editor:backspace-to-beginning-of-line` to
`editor:delete-to-beginning-of-line`.
Fix#1791
Kirill Nikitin
111b5d1fbe