Added Readefine Desktop

Readefine Desktop beautifies Google Reader articles, RSS, plain text
and HTML for easy reading. View multiple articles in a fluid, magazine
style layout or navigate one article at a time in a book like
multi-column layout. Tweak settings like font size, justification,
column width, etc. for that perfect look.
Merge pull request #3550 from alebcay/readefine-desktop

Added Readefine Desktop