Work on Core 2.5.9

	* Feature #385 - Sanitize filenames for files uploaded
	* Feature checkbox groups now have a toggle all option
	* Added a "keepdots" parameter to the str_to_url function.  Useful for filenames
	* System form elements now jsonencode their values.  Allows multi-values to be used in the unique key
	* Minor bug in the updater template.  Needed to use version_compare instead of "<="