more licensing stuff
- rewrote getPhotos()/Properties()
- need to finish getThumbs() and loadFolder() (oops forgot about it)
- also added (unfinished) getAllUniqueKeys(), so clients can
use getSpecificPhoto() more easily
- todo: add caching to getSP()
- also briefly documented DataType
removed unnecessary files
- completed getAllUniqueKeys() and getThumbs()
- re-implemented how photos are written (new StreamWriter which
implements Runnable, to allow for async writing)
- PhotoPanel now retrieves properties properly
- TODO: fix displaying properties, finish adding caching
- still don't know what to do with loadFolder() (move or not?)
- getSpecificPhoto() now caches properly, and async
- more comprehensive documentaion, esp. for columnNames and columnTypes
  (and their restrictions)
- (gradually) converting to javadoc-style comments
- fixed temp files not deleting on exit (+minor changes, dispose() method
  to PhotoPanel)
- TODO: finally do loadFolder(); display properties;
- minor "fix" to SettingsDialog to make the textboxes taller
updated README