git: added .gitignore, copied from RIOT
git: added .gitignore, copied from RIOT

miri64/RIOT,miri64/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,ant9000/RIOT,kaspar030/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,miri64/RIOT,RIOT-OS/RIOT,ant9000/RIOT,jasonatran/RIOT,kaspar030/RIOT,ant9000/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,miri64/RIOT,ant9000/RIOT,jasonatran/RIOT,miri64/RIOT,kaspar030/RIOT,kaspar030/RIOT,ant9000/RIOT,jasonatran/RIOT