Use 7-zip library for various packer format support

[ono]

I just wanted to suggest integrating 7-zip project which is GNU LGPL into FL for packing/unpacking various compression formats, many more than what FL can currently handle.

[csaba]

Thanks for the tip ono - we did do some research into this with the purpose of extending ForkLift's archive handling capabilities ourselves, and 7-zip did come up.
But we decided to let this project rest for some time, as are hands are full with higher priority projects at the moment.
Still, we'll get back to this in the future. Thanks again.