Merge of r5117, r5123: allocation errors handing during upgrade.

*) Core: guard against failed allocation during binary upgrade.
   Patch by Piotr Sikora.

*) Core: fixed resource leak if binary upgrade fails due to no memory.
   Found by Coverity (CID 992320).


git-svn-id: svn://svn.nginx.org/nginx/branches/stable-1.2@5159 73f98a42-aea0-e011-b76d-00259023448c
Merge of r5127: language in a comment.

Fixed language in a comment preceding ngx_http_index_handler().


git-svn-id: svn://svn.nginx.org/nginx/branches/stable-1.2@5160 73f98a42-aea0-e011-b76d-00259023448c
Merge of r5129: split clients configuration parsing.

Split clients: check length when parsing configuration.


git-svn-id: svn://svn.nginx.org/nginx/branches/stable-1.2@5161 73f98a42-aea0-e011-b76d-00259023448c