Release of version 0.9.1

Changed

• Re-licensed to GPLv2.

Added

• Improve Windows time support by using QueryPerformanceCounter and GetSystemTimePreciseAsFileTime. Time precision on Windows 10 can now reach 100ns.
• Add syslog support for the server (--syslog flag).
• Add a SmokePing probe, available from SmokePing 2.7.2. It's possible to copy the
  code into older versions.
• Update OM2P build to use the new MIPS softfloat support in Go 1.10.

Changed

• Re-write git history with new email address.

Removed

• Stop disabling GC on client and remove --gc flag from server as disabling GC no longer offers a demonstrable performance benefit. See The Journey of Go's Garbage Collector.

Fixed

• Fix potential client race at startup.
• Fix issue on platforms with timer resolution not accurate enough to measure server processing time (closes #13).
• Change handled interrupt signals to only os.Interrupt and syscall.SIGTERM to fix Plan 9 build.
• Various documentation fixes.