-dnl Xmllint is used in the rules to build the documentation. It is not actually necessary,
-dnl but is used for post-build consistency checks. Thus, non-developers can live without it.
-dnl However for it to be useful, it needs to be a certain version and have certain features.
-dnl The macros below check that it the xmllint available is up to scratch. If it isn't
-dnl then a dummy /bin/echo is subsituted instead.
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