Small changes to qgroup docs #818

Job	Run time
Linux CentOS 7	3m 45s
Linux fedora latest	4m 14s
Native Linux (WError)	5m 9s
Native Linux (libc++ debug)	6m 7s
Native Linux (c++17)	5m 5s
Cross mingw64 DLL	11m 8s
Cross mingw64 static	11m 55s
RTEMS5	14m 23s
Native Linux with clang	4m 44s
Native Linux with clang ubsan	5m 26s
Native Linux with libevent stable	4m 50s
Native Linux with 7.0.2	5m 20s
Native Linux with 3.15	3m 49s
Native Linux with 3.14	6m 17s
OSX	3m 27s
vs2019 DLL	8m 33s
vs2019 static	8m 9s
	1h 52m 21s

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