This makes them show up in the reference, even if the text itself isn't
the most descriptive.

These have been found with

    grep -Przon '\n\ntypedef struct.*?\{' -- include
    grep -Przon '\n\ntypedef enum.*?\{' -- include

FLAG_BITS only seems to be used internally

Add support for setting the SSL CA location

This allows users to specify self-signed certificates, or to provide their
own certificate stores on limited platforms such as mobile phones.

The default cache size is 256 megabytes, not megabits as claimed in the
docs.

This survived the last round of culling, as the signature is only in the
comments.