config: fix omicron laser config

from actual tests
gui: getSpectrum Stream method refactored
Changed the uses of 'im_func' and 'im_self' to the more modern, Python 3 compatible, '__func__' and '__self__' attributes
gui: fixed view selector thumbnail bug
Merge branch 'development'
model: add tests for va unsubscribe

also use new style for exceptions
Merge branch 'master' of vpn.delmic.com:odemis