mod_http_oauth2: Support HTTP Basic auth on token endpoint This is described in RFC 6749 section 2.3.1 and draft-ietf-oauth-v2-1-07 2.3.1 as the recommended way to transmit the client's credentials. The older spec even calls it the "client password", but the new spec clarifies that this is just another term for the client secret.

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summary: Log a message once per minute
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This module sends `-- MARK --` to the log once per minute. This may be
useful to give a sense of how busy the server is or see that logging and
timers are still working.