Fixed spellings, updated self-update URL and other URLs
Updated repository from ingenuitas to sightmachine.
README: Add installation instructions for Fedora 18
Merge pull request #444 from davidk/develop-fedora-install

README: Add installation instructions for Fedora 18. Thanks for helping us out. I am sure the Fedora community will appreciate this.
Merge pull request #441 from codetab/ingenuitas-sightmachine

Updated repository from ingenuitas to sightmachine.
Merge pull request #437 from codetab/Shell-Tutorial

Fixed spellings, updated self-update URL and other URLs