Log message:
Update mbuffer to 20150412

20150412:
- fix: watchdog cannot do its job if it is cleaned up to early
- fix: clear sa_flags and sa_mask before use, although ignored

20141227:
- added option --pid to print PID of current process
- updated usage to include option -W
- man page formatting fixes
- configure updates
- support compiling on systems that do not define PATH_MAX

Log message:
Use BROKEN_ON_PLATFORM for "needs sysctl bits".

Log message:
Import mbuffer-20140310 into pkgsrc, packaged by Brian Bennett.

mbuffer is a tool for buffering data streams with a large set of
unique features:

 * direct support for TCP based network targets (IPv4 and IPv6)
 * ability to send to multiple targets in parallel (distribution mode)
 * support for multiple volumes
 * I/O rate limitation
 * high/low watermark based restart criteria
 * configurable buffer size
 * on the fly MD5 hash calculation
 * highly efficient, multi-threaded implementation

It is especially useful, if you are writing backups to fast tape drives
or libraries.