add new environment variable setup to links controller
Merge branch 'master' of https://github.com/ReadUpCode/readup
add twitter button to each item in list
add more fixes to get twitter button on each item
add in code to only have one version of an item. append tags and categories to original item on subsequent reposts of same item.
Merge branch 'master' of https://github.com/ReadUpCode/readup
Merge pull request #94 from DougKong/master

add back in code to allow only 1 version of an item.  add in twitter button for each item.