Fix broken xmllint validation.

An older version of xmllint failed to validate a broken
URL.

The URL led to nowhere, so this also fixes a few dangling
links.

Use olink & targetptr instead of link & linkend, as is the
convention in the rest of the manual.

Give internal links a bit longer names (as is also convention
in the rest of the manual).

The final version of odnoklassniki patch did not include the
most important part - delayed free of salloc memory.

Make a quick & dirty fix to the point.