Fixed two broken links.
Emphasized the fact that, since 2011, I work as a consultant and not as an employee.
Removed mountebank from open source contributions. Once I have contributed something major like a new feature (as I have currently proposed in the issue tracker) or addressed a bug I may include the project again in the list.
Removed the information area (Categories, Date, etc) from Screencasts page since they are not published yet.
Made the Background page shorter to be easier and quicker to read.