Recent Linux versions started to return EOPNOTSUPP to getsockopt() calls
on unix sockets, resulting in log pollution on binary upgrade.  Such errors
are silently ignored now.

The accept_filter and deferred options were not applied to sockets
that were added to configuration during binary upgrade cycle.

Signed-off-by: Piotr Sikora <piotr@cloudflare.com>

This patch fixes incorrect handling of auto redirect in configurations
like:

    location /0  { }
    location /a- { }
    location /a/ { proxy_pass ... }

With previously used sorting, this resulted in the following locations
tree (as "-" is less than "/"):

        "/a-"
    "/0"    "/a/"

and a request to "/a" didn't match "/a/" with auto_redirect, as it
didn't traverse relevant tree node during lookup (it tested "/a-",
then "/0", and then falled back to null location).

To preserve locale use for non-ASCII characters on case-insensetive
systems, libc's tolower() used.

Found by using auth_basic.t from mdounin nginx-tests under valgrind.

==10470== Invalid write of size 1
==10470==    at 0x43603D: ngx_crypt_to64 (ngx_crypt.c:168)
==10470==    by 0x43648E: ngx_crypt (ngx_crypt.c:153)
==10470==    by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297)
==10470==    by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240)
==10470==    by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121)
==10470==    by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895)
==10470==    by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878)
==10470==    by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852)
==10470==    by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283)
==10470==    by 0x456A91: ngx_http_process_request_line (ngx_http_request.c:964)
==10470==    by 0x457097: ngx_http_wait_request_handler (ngx_http_request.c:486)
==10470==    by 0x4411EE: ngx_epoll_process_events (ngx_epoll_module.c:691)
==10470==  Address 0x5866fab is 0 bytes after a block of size 27 alloc'd
==10470==    at 0x4A074CD: malloc (vg_replace_malloc.c:236)
==10470==    by 0x43B251: ngx_alloc (ngx_alloc.c:22)
==10470==    by 0x421B0D: ngx_malloc (ngx_palloc.c:119)
==10470==    by 0x421B65: ngx_pnalloc (ngx_palloc.c:147)
==10470==    by 0x436368: ngx_crypt (ngx_crypt.c:140)
==10470==    by 0x489D8B: ngx_http_auth_basic_crypt_handler (ngx_http_auth_basic_module.c:297)
==10470==    by 0x48A24A: ngx_http_auth_basic_handler (ngx_http_auth_basic_module.c:240)
==10470==    by 0x44EAB9: ngx_http_core_access_phase (ngx_http_core_module.c:1121)
==10470==    by 0x44A822: ngx_http_core_run_phases (ngx_http_core_module.c:895)
==10470==    by 0x44A932: ngx_http_handler (ngx_http_core_module.c:878)
==10470==    by 0x455EEF: ngx_http_process_request (ngx_http_request.c:1852)
==10470==    by 0x456527: ngx_http_process_request_headers (ngx_http_request.c:1283)
==10470==

The same path names with different "data" context should not be allowed.

In particular it rejects configurations like this:

    proxy_cache_path /var/cache/ keys_zone=one:10m max_size=1g inactive=5m;
    proxy_cache_path /var/cache/ keys_zone=two:20m max_size=4m inactive=30s;

An instance of ngx_path_t is already zeroed by ngx_pcalloc().

It initializes the "data" pointer of ngx_path_t that will be checked after
subsequent changes.

Casts between pointers and integers produce warnings on size mismatch.  To
silence them, cast to (u)intptr_t should be used.  Prevoiusly, casts to
ngx_(u)int_t were used in some cases, and several ngx_int_t expressions had
no casts.

As of now it's mostly style as ngx_int_t is defined as intptr_t.