Remove tab chars from retro C sources.
Merge pull request #92 from oliverschmidt/master

Remove tab chars from retro C sources.
Minor README updates.
Merge pull request #96 from oliverschmidt/master

Minor README updates.
Merge branch 'master' of github.com:contiki-os/contiki into feature-z1-hmc5843
added CFLAGS to z1 examples makefile