Group system state cache methods for Doxygen.

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@13731 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd
add asynchronous ROI capability

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@13732 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd
simplify

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@13733 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd