version 0.3.2, 2012-05-10
  * fixed bug in handling of :src_addr option that could cause a segfault

version 0.3.1, 2011-12-15
  * fixed to retry 'select' system call after EINTR

version 0.3.0, 2011-09-30
  NOTE: You must run mper v0.4.0 to use all of the new features in this
        release.

  * added new sample scripts: mper-trace, mper-trace-convertor
  * added support for IP options: prespecified timestamp and record route
  * added setting of TTL, ICMP checksum, timeout, TOS, required reply count,
    and source IP address to use in probes (but not for spoofing)
  * scripts are now installed in Ruby's bin directory during gem install

version 0.2.0, 2009-12-15
  * added --spacing: spacing (ms) between probes
  * added --concurrency: max targets to probe concurrently

version 0.1.0, 2009-12-14
  * added support for using rb-mperio as a generic nonblocking I/O event loop
    (specifically to handle nonblocking I/O for Marinda::Client)

version 0.0.2, 2009-xx-xx
  * improved mper-ping:
     - added support for specifying the probing method
     - added support for targets on command line
     - added --full output

version 0.0.1, 2009-09-28
  * initial version