* Enforce limit of 8K on regex searches that have no limits

* Enforce limit of 8K on regex searches that have no limits
* Allow the l modifier for regex to mean line count. Default
  to byte count. If line count is specified, assume a max
  of 80 characters per line to limit the byte count.
* Don't allow conversions to be used for dates, allowing
  the mask field to be used as an offset.
* Bump the version of the magic format so that regex changes
  are visible.