** Added UserImage entity
** Added modified property into UserImage entity
** Removed profileImage property from User entity
** Changed UserController from RequestScoped -> Dependent
** Added methods for handling profile images into UserController
** Removed profile image references from CompactUserBean
** Removed profile image nulling from MaterialController deleteMaterial
method
** Added getLoggedHasProfileImage method into SessionBackingBean
** Changed profile image servlet to work with UserImage entity instead
of user.profileImage
** Fixed index view to work with changed user profile image
** Fixed profile view to work with changed user profile image
** Added gravatar support into ProfileImageServlet (fallback if local
profile image is missing)
** Removed image existence checks from profile.xhtml so that gravatar
fallbacks will be used 
** Removed unused css rule for imageless users
** Added gravatar support into forum
** Added gravatar support into index page
** Removed unused user-anonymous icon
** Added profileImageSource property into User entity
** Added method to update profile image source into UserController
** Added support for profile image source into ProfileImageServlet
** Added profile image source selection support into editprofile view