Added version hash to admin interface

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Updated rendering of hashes

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Added hashFile() to mediaHandler interface

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Added default hashing to version _onPreSave()

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Updated hash task to use mediaHandler hasher

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Reuse already uploaded files

Signed-off-by: Tom Wright <tom@inflatablecookie.com>