add DigestUtil.digestFile function
unify LocalFileShareMessage and RemoteFileShareMessage
makes LeafMessage.isHidden abstract
makes business logic out of http parse logic
makes logout logic in session control service
package re struct
makes Message simpler
add query type
add some query class
message query proto implement
add SearchMessageQuery deserialize
more message service implement
more MemoryDataStore implement
makes ErrorMessage to ResponseMessage and more generic
add sessionFilter ,makes servlet access path more generic
add digestId method comment
makes "SHA-1" a shared static field
implement CompositeMessage digestId function
add FileShareMessage comment
add SendMessageServlet