Small changes to qgroup docs #817

Job	Run time
Linux CentOS 7	3m 41s
Linux fedora latest	4m 9s
Native Linux (WError)	5m 14s
Native Linux (libc++ debug)	5m 54s
Native Linux (c++17)	4m 59s
Cross mingw64 DLL	11m 25s
Cross mingw64 static	12m 1s
RTEMS5	14m 9s
Native Linux with clang	4m 38s
Native Linux with clang ubsan	5m 2s
Native Linux with libevent stable	5m 4s
Native Linux with 7.0.2	5m 6s
Native Linux with 3.15	3m 51s
Native Linux with 3.14	6m 32s
OSX	3m 11s
vs2019 DLL	9m 40s
vs2019 static	9m 32s
	1h 54m 8s

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