Installation procedure
Merge branch 'master' of github.com:ewan-klein/carneades into docs
Fix typo on doc install procedure
Add igraph installation method for ubuntu 12.04
Fix link typo
Edited installation procedure for linux users
Fix list in install igraph section
Link to install section was wrong. 

Note: let's hope commonMarkdown comes soon.
Merge pull request #2 from edran/docs

Add some installation documentation