Add an option to wipe free space

Have an option to "wipe all free space" on the hard drive or just to "wipe space" on the part of the hard drive that the files being removed by CCleaner.

There already is ...

Have an option to "wipe all free space" on the hard drive

= set 'Wipe Free Space' plus 'Secure Deletion'

or just to "wipe space" on the part of the hard drive that the files being removed by CCleaner.

= just set 'Secure Deletion'

If you want files securely deleted make sure you allow CCleaner to handle cleaning the Recycle Bin, then just delete files normally with Windows, and when you run CCleaner it will secure delete them.