Reject invalid options set by recipes

When recipes mutate the options, we should not allow invalid syntax otherwise
it gets written in .installed.cfg and generate invalid configparser syntax.
3 jobs for fix/escape_options in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.Buildout.UnitTest-EscapeOptions.Python2

00:17:03

passed SlapOS.Buildout.UnitTest-EscapeOptions.Python3

00:22:41

failed SlapOS.Buildout.UnitTest-Master.Python2

00:06:17