Merge pull request #78 from marioa/2013-05-oxford-dtc

Added git material based on the 2013-04-manchester bootcamp.
Removed hyperlinks at the end and changed schematic diagrams of arrows to point from child to parent.
Merge branch '2013-05-oxford-dtc' of git://github.com/swcarpentry/boot-camps into 2013-05-oxford-dtc
Welcome slides based on the 2013-04-manchester bootcamp.