When clearing the [CR]LF in a line continuation, we would continue
replacing any [CR|LF|HT|SP] characters up until the end of the buffer,
possibly overwriting later [CR]LFs. Fix this by only unconditionally
overwrite one [CR]LF, and then only replace [HT|SP] with SP to keep with
previous behaviour.

Update r00494.vtc to include multiple line continuations to make sure they
are parsed.

The end of http1_dissect_hdrs ends with skipping over the final [CR]LF
that marks then end of the headers. Currently that skip is optional, that
is, it is skipped if it was present.

This patch adds an assert if the final [CR]LF is not found when finishing
the parsing. HTTP1_Complete guarantees that it is there, if not we would
not have started parsing the request or response in the first place, and
if it is missing, there must be an error in the parsing leading up to it.

In http1_splitline, if the third field is missing, we would still set the
txt.b value to where the field would have been, with a NULL txt.e
entry. This would cause http_Proto to attempt to parse the values
there. Fix this by only setting the .b and .e if the third field was
present.

When parsing a request like this, "GET /\n\n", the first NL would be
overwritten by nul guard inserted after the 2nd field, and the second NL
would be overwritten by the nul guard after the missing 3rd field. This
would cause http1_dissect_hdrs to attempt to decode the body as headers.

The proto field is optional in HTTP, so it may not be set. Set the proto
to 0 also for a NULL value instead of segfaulting if it were NULL.

The macros vct_iscrlf() and vct_skipcrlf() may look at one or two bytes
after its pointer value, causing OOB reads. This would allow
http1_dissect_hdrs to wrongly see a CRLF when one wasn't there (the last
LF left over in the bufer from the previous request).

Change the macros to inline functions, and harden them by always sending
the end pointer so that they can't overflow.

vct_iscrlf() will return an int value of 0 for no [CR]LF, 1 for LF and 2
for CRLF.

vct_skipcrlf() will return the pointer having been skipped 0, 1 or 2
bytes.

Encoding and decoding are as much a function as handling blobs,
in particular with transcode().

Closes #2870

Conflicts:
	include/tbl/vsl_tags.h

We can use the NOSUP_NOTICE instead.

Addresses the doc part of #2872.

It's really not obvious, and if it weren't for other tests covering
probes it wouldn't be enough by itself to verify what it needs to.

I was wrong, or I lied. This is the final cleanup.

This time, once and for all.

The due time of the probe which has just finished may be earlier than
the previously earliest due time, so vbp_thread needs to be woken up to
update the nxt value

Fixes #2976

Allow VMOD writers to permit with NULL_OK flag.

Only call object destructor on initialized objects.

Fixes #2839

Conflicts:
	lib/libvmod_debug/vmod.vcc

And make it clear that we steal the reference at this point.

Solaris, (remember Solaris?) will return connection related errnos
on fd metadata operations such as ioctl(2), [gs]etsockopt(2) etc.

We propagated these errors up from VTC_(non)blocking() which could,
theoretically, bail out earlier than it would otherwise have done.
This complicated code far more than it speeded anything up.

Instead just ensure that any errors returned are indeed connection
related, and then ignore them, and let Solaris deal with the broken
connection same way as other operating systems.