Fix an issue where the order of symbol definition determined if
code could compile or not.

Fixes #1569
Set Vary: Accept-Encoding if we munge the gzip status.

Patch by:	fgs  (with minor modifications)
improve legibility
Escape question marks in C-strings to avoid accidentally generating
tri-graphs.

Fixes #1566
Fix readline finding on FreeBSD -current
Don't bother with busyobj delivering already completed objects.

(This doesn't _quite_ close the race, but at least test c00034 is
much more stable now.)
Disable streaming in this test
white space nit
Give vrt_ctx a "double now" timestamp for use in VCL/VRT/VMODs
Fix sensitivity for header token matching. Rename GetHdrData -> GetHdrToken

Section 4.2 (Messages Headers) of RFC2616 defines field (header) name as case
insensitive, but the field (header) value/content may be case-sensitive.

http_GetHdrToken looks up a token in a header value and the rfc does not say
explicitly if tokens are to be compared with or without respect to case.

But all examples and specific statements regarding tokens follow the rule
that unquoted tokens are to be matched case-insensitively and quoted tokens
case-sensitively.

Fixes #1582
strings.h doesn't get included anywhere else where strncasecmp() is used
Update filename references
WS_Reserve shouldn't round down if we're not asking for too much
fight ocpd
Change exit code documentation so highest is most severe. Dont mention exit(4)

After discussion with phk: exit(4) is a real exception, we should abort() whenever
possible.

The error codes patch is still to be committed.