Refactor versionMismatch logic
Make 'ser' protected for replacement
Add Memoizer.main method
Fix NPE by passing imageCount to Coordinates

On deserialization from the memofile by Kryo, a call to hashCode
failed with a NPE since no ZeissCZIReader instance was available.
Rather than relying on the outer class, image count is now passed in
actively for use by hashCode.

Where possible, other inner classes have also been made static.
Several remain which are not.