From libpubsub 0.5.0 to 0.5.1
- the client is able to read the message broker address from the environment
  variable PUBSUB_BROKER
- added conversion routines between binary data and hexadecimal strings
- added support for very large messages over TCP
- several minor bugfixes and cosmetic changes
- embedded user's guide into doxygen generated docs

From libpubsub 0.4.0 to 0.5.0
- finally added tcp support ;-)
- added transport pool
- added own c++ wrappers for Pthreads (needed for TCP-transport)

From libpubsub 0.3.1 to 0.4.0
- added own implementation of c++ socket wrappers (no need for cppsocket any
  more)
- lower level parts of libpubsub have been rewritten, to allow more easier
  integration of tcp support

From libpubsub 0.3 to 0.3.1
- configure now stops if libcppsocket could not be found and gives a hint
  where to fetch it
- the psc client now accepts empty messages

From libpubsub 0.2 to 0.3
- fixed a bug, which caused a compilation error if the unit++ test framework
  was not installed (which is only necessary for testing)
- implemented automatic discovery of message broker (if no specific message
  broker ip is provided by the user)
- moved most of the in-source documentation from the source files to the
  header files

From libpubsub 0.1 to 0.2
- added support for autotools