PatternOverlay: made intent clearer in parent class by declaring one method abstract and variables private that child classes don't need

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14339 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd
PatternOverlay: further refined structure of master/derived overlay classes

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14340 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd
PatternOverlay: javadoc update only

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14341 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd