Improved readme sample code

Changed property isLittleEndian from a variable to a let constant.  It'll never change.  Update to #PR20.

Fix endian bug in hostnameAndPort function

The hostnameAndPort() function forgets to check endian-ness of host
before returning port number.

Bug fix: remoteConnectionClosed should only be set in the readDataIntoStorage() function since that's the only place where we can actually tell that it actually happened.