moved style settings for displaying artifacts from Content object to the viewer itself with StyleSheet
simplified flow of hex viewer a bit
Improved layout and styling of ingest messages to have style sheets and consistent look and feel
Updated developer docs for content viewers and added example module
Fixed contentviewer behavior so that isSupported is not called with null
Merge branch 'master' of github.com:sleuthkit/autopsy
updated API doc
Updated docs for ContentViewers
Added picture to doxygen docs
Updated doxygen for image