[PATCH 0 of 5] error_page/return cleanup

[Maxim Dounin]

Hello!

Here is a set of patches which resolves a number of issues with
"error_page" and "return" directives, as well as special response
handling in general.  Please see patches for more information.

Relevant test cases are available in test suite, see this commit:

http://mdounin.ru/hg/nginx-tests/rev/1e1975cd25ef

Tests which happen to fail in 0.8.53 are marked as TODO.

Maxim Dounin