removed unnecessary semicolons, imports, unused labels
remove unused variables
remove unnecessary syntax (casts)
make serialVersionUID fields private
remove warnings: @Override and switch fall-through
simplify 'if' statements where clauses don't end normally
mark deprecated unused private constructor as unused
rename field 'self' to 'localNode' in AbstractConnection

field 'OtpLocalNode self' was colliding with 'OtpSelf self' in
OtpConnection
rename OtpNode.Acceptor.port to acceptorPort

was colliding with OtpLocalNode.port
rename OtpNode.flags to connFlags

was colliding to AbstractNode.flags
remove warnings from OtpMD5
add 'break' statements to make compiler happy
renamed method parameters hiding fields in the class
keep all method parameters final
handle warnings about potential null pointers
don't warn about some unused fields/variables
silence 'potential resource leak' warnings

OtpInputStream and OtoOutputStream don't need closing (they are
ByteArray*Streams)
fix warning about Socket's InputStream not being closed

The warning is issued if we assign the stream to a variable. The stream
is getting closed together with the socket.