Release 1.6

Stable version 1.6 of PhpZip is now fully available on the CVS repository (tag release-1-6). I did also commit on teh same branch the release 1.5 for historical reason and in separe branches versions before 1.5.

I will in the near futur commit the Unstable/development work for futur version 1.7.
It will add some improvments and web design facilities (using javascript more intensivelly).