calibration-viewer.py - force blocking behavior.
calibration-viewer.py - force blocking behavior.

not sure when this became a problem but at some point blocking seemed
to no longer be the default on my OSX machine. Not sure if this is a some
machine specific setting I made. But it doesn;t seem problematic to just
force this to be true and it prevents a few moments of confusiton when
you update from github and the plots no longer stay displayed. Seems like
it will be handy to leave this setting in the main repo.

tobeycarman/dvm-dos-tem,tobeycarman/dvm-dos-tem,tobeycarman/dvm-dos-tem,tobeycarman/dvm-dos-tem,tobeycarman/dvm-dos-tem,tobeycarman/dvm-dos-tem