Fix "Keep shutter open" for channels

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14406 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd
Clean up imports

Remove unused and duplicates; sort

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14407 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd