core: default tcp read buffer size set to 16kB
core: pv print default buffer size set to 8kB
tm: default value for failure_reply_mode set to 3

- discard previous replies if a new serial forking step is done
tm: updated readme with default value for failure_reply_mode

- fixed broken ending section tag in functions file
core: default size for shared memory is 64MB

- decent size at least for 64b architecture where pointer overhead is
  bigger
Makefile.defs: version set to 4.3.0-dev1