Change typos in comments.

Change typos in comments.
(forms-delete-record, forms--update): Use `delete-region' instead of
`kill-line' to avoid messing around with the kill ring.

Release 2.1 for Emacs 19.19.
(forms--process-format-list): No need to prepend a text item anymore.
(forms--ro-modification-start): Renamed to `forms--iif-start.
(forms--ro-properties): Renamed to `forms--iif-properties'.
(forms--romh): Renamed to `forms--iif-hook'.  Rewritten to use
`insert-in-front-hooks' instead of `modification-hooks'.
(forms--romh-post-command-hook): Renamed to
`forms--iif-post-command-hook'.  Rewritten to use
`insert-in-front-hooks' instead of `modification-hooks'.
(forms--make-format, forms--make-format-elt-using-text-properties):
Use `insert-in-front-hooks' instead of `modification-hooks'.
Remove `forms--electric' code.  Use `front-sticky' and
`rear-nonsticky' text properties to control the insertion of text
between read-only fields.
(forms--show-record): Remove `forms--electric' code.