Exposed the arguments to gzcompress by adding public variables to the Zip library.
Updated changelog to include changes to the Zip Library.

Signed-off-by: garrettair <garrettair@gmail.com>
Updated Zip Library documentation to mention compression features.

Signed-off-by: garrettair <garrettair@gmail.com>
Merge pull request #3341 from garrettair/gzcompress-arguments

Adds Compression options to Zip Library