Merge of r4785, r4795, r4811, r4812, r4816, r4822: coverity.

Merge of r4785, r4795, r4811, r4812, r4816, r4822: coverity.

*) Resolver: fixed possible memory leak in ngx_resolver_create().

*) Explicitly ignore returned value from unlink() in ngx_open_tempfile().

*) Explicitly ignore returned value from close() in ngx_event_core_init_conf().

*) Added three missing checks for NULL after ngx_array_push() calls.

*) Crypt: fixed handling of corrupted SSHA entries in password file.

*) Mark logically dead code with corresponding comment.

Found by / prodded by Coverity.