Upgrade kicad to stable 20130325

- upgrade kicad to stable 20130325, and kicad library to r220
- have kicad depend on wxGTK29 and cups -- prevents build errors
- changed fetchbzr to export only (only use is for kicad library)
- removed keep-dot-files option from nix-fetch-bzr (only use is for kicad
library)
- have fetchbzr and nix-fetch-bzr ignore SSL certificates