Refactor PhotoInfoController

[harri]

PhotoInfoController? is getting convoluted and difficult to maintain. Some ideas to improve it:

• Extract it to its own package
• Change PhotoInfoView? interface so that it does not have separate methods for each field. This would significantly ease adding new fields to PhotoInfo?
• Currently ColorSettingsDlg? uses its own methods for sending notifications to preview window. Most likely it could also use the mechanisms provided by PhotoInfoController?. After all, that is the reason it was built in the first place.