Update README.md

Remove the windows stuff. No longer relevant
Refactoring to help simplify grunt plugin
Merge branch 'master' of github.com:bekk/retire.js
Several updates to simplify grunt plugin
Fixing package.json reference
Bumping version
Update README.md with global install switch

To use retire it needs to be installed globally and requires the -g switch when installing
Merge pull request #22 from tdm00/patch-1

Update README.md with global install switch
Update blogpost.md
Update README.md
Added a section about the Grunt plugin, plus some language fixes
mistype
Merge pull request #23 from hajdbo/patch-1

mistype
Merge pull request #24 from christianmosveen/master

Added a section about the Grunt plugin, plus some language fixes
Added link to grunt-retire in readme
Update blogpost.md
Update README.md
Adding older jquery versions
Merge branch 'master' of github.com:bekk/retire.js
Updating jQuery. Vulnerable below 1.6.3 http://research.insecurelabs.org/jquery/test/