add activate-hs --skip option
add activate-hs --skip option

This option causes the script to skip linking, only registering packages.

http://projects.haskell.org/pipermail/haskell-platform/2014-August/002994.html

bgamari/haskell-platform,erantapaa/haskell-platform,gbaz/haskell-platform,bgamari/haskell-platform,gbaz/haskell-platform,erantapaa/haskell-platform,ardumont/haskell-platform,thomie/haskell-platform,ardumont/haskell-platform,erantapaa/haskell-platform