Drop unused, previously sscanf() target variables

Submitted by: wrowe
Backport: r1756821

Drop redundant == --rrl_none evaluation
Submitted by: rpluem
Backport: r1756823

server/protocol.c (read_request_line): Fix compiler warnings with GCC.
Submitted by: jorton
Backport: r1756824

Correct request header handling of whitespace with the new possible config of
HttpProtocolOptions Unsafe StrictWhitespace

I have elected not to preserve any significance to excess whitespace in the
now-deprecated obs-fold code path, that's certainly open for discussion.

This can be reviewed by tweaking t/conf/extra.conf to switch Strict to Unsafe.
Submitted by: wrowe
Backport: r1756847

A band-aid to resolve an immediate IBM MVS'ism
Submitted by: wrowe
Backport: r1756849

Resolve Netware (and other arch) build error for non-portable isascii()
Submitted by: wrowe
Backport: r1756934

Generally, the cart comes before the horse, this mirrors apr_lib.h
Submitted by: wrowe
Backport: r1756937

After lengthy investigation with covener's assistance, it seems we cannot
use a static table. We cannot change this to dynamic use of the local iconv
without build changes to avoid such use on cross-platform builds.

I'm satisfied if we trust iscntrl to at least catch all the most lethal
C0 Ctrls (we are promised it catches bad carriage control/line endings)
and leave this in the short term with an XXX to revisit at a future time.

The token stop never needed this table, because we can use the affirmative
list of token characters to define it.
Submitted by: wrowe, covener
Backport: r1756946



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x-merge-http-strict@1769664 13f79535-47bb-0310-9956-ffa450edef68