correctly catch invalid cmd options, fix error exit codes
improve error message when instancedata not found
cache output of 'uname -i' as it certainly won't change during the run of SUSEconnect
Merge remote-tracking branch 'origin/master' into review_140813_small_connect_improvements_that_came_out_of_card_2149
fix architecture caching in tests
test for non existing instance data file
use class instance var
improve test for instance data not found
use log.fatal instead of puts
use file error
test FileError
Merge pull request #161 from SUSE/review_140813_small_connect_improvements_that_came_out_of_card_2149

[Review] Request from 'digitaltom' @ 'SUSE/connect/review_140813_small_connect_improvements_that_came_out_of_card_2149'