These are mostly comments in the code. A few error messages were fixed
and are of low enough importance not to deserve a backport. Some regtests
were also fixed.
This test occasionally fails on the Travis CI tests because the
"in progress" bit is sometimes still set (or set again) in the show
servers state output and is not expected in all regexes (some do
already cover it), like in this one :
https://travis-ci.com/haproxy/haproxy/jobs/221324920
Let's extend the remaining ones to accept this as well. Other tests
do not seem affected as they only expect sequences of digits there.
