New release of stack, a build tool.

Changes:

General information and download links (now with package repositories for CentOS, Fedora, and Debian):

If you already have stack-0.1.1.0, you can upgrade using:

stack upgrade --git && stack upgrade

   

[normally just 'stack upgrade' will suffice, but due to my flub in the last release we ended up with a stack-9.9.9 on hackage which can't be removed (see https://github.com/haskell/hackage-server/issues/382), and you have to get the stack version that knows to ignore it first]