Force update of doc/flycheck.texi
Rebuild the Texinfo manual
Fix test name
Switch to a different Golang PPA

gophers/go is frozen and unmaintained.
Be very patient while waiting for Haskell builds
Update test case for Less

Recent less versions have more exact error positions
Support multiline Go error messages

Also update the Go build test cases for the more recent Go versions we
use now.
Update Texinfo manual