Commit 3c630f9b0af097663a64e5c875c580aa9808a92b partially reverted the
changes from commit dd7521bcc1b7a6fcb53c31f9bd1192fcc884bd56 because of
the problem that strcpy_url() was modified unilaterally without also
modifying strlen_url(). As a consequence strcpy_url() was again
depending on ASCII encoding.
This change fixes strlen_url() and strcpy_url() in parallel to use a
common host-encoding independent criterion for deciding whether an URL
character must be %-escaped.
Closes#2535
With commit 4272a0b0fc49a1ac0ceab5c4a365c9f6ab8bf8e2 curl-speficic
character classification macros and functions were introduced in
curl_ctype.[ch] to avoid dependencies on the locale. This broke curl on
non-ASCII, e.g. EBCDIC platforms. This change restores the previous set
of character classification macros when CURL_DOES_CONVERSIONS is
defined.
Closes#2494
... since the libc provided one are locale dependent in a way we don't
want. Also, the "native" isalnum() (for example) works differently on
different platforms which caused test 1307 failures on macos only.
Closes#2269
