Merge pull request #107 from maarzt/fix-memory-leaks

src/main/java/bdv/tools/HelpDialog.java

src/main/java/bdv/tools/RecordMaxProjectionDialog.java

src/main/java/bdv/tools/RecordMovieDialog.java

src/main/java/bdv/tools/VisibilityAndGroupingDialog.java

src/main/java/bdv/tools/brightness/BrightnessDialog.java

src/main/java/bdv/ui/BdvDefaultCards.java

src/main/java/bdv/util/DelayedPackDialog.java

src/main/java/bdv/viewer/ViewerPanel.java