Added offset calculation for carousel when allowWrap = false

[beaubbe]

There was no offset calculation for carousel when allowWrap = false. On resize, the offset was always 0.

[leaski]

Massive help for dealing with resizing causing the carousel to go back to the first slide.

The only problem I had with the code for me was that the active class was using the slideActiveClass default of 'cycle-slide-active' instead of 'active'