fixed gcc4.7 build error (sleep and usleep undefined)
changed timeout to si unit (ms -> s)
bugfixed segfault if a freq with zero was set (default freq = 10Hz)
console feedback if mode finished
Merge branch 'groovy_dev' of git://github.com/ipa320/cob_driver into groovy_dev
Merge pull request #65 from ipa-bnm/groovy_dev

cob_light bugfix and gcc version related build errors