Fix SetHandler proxy:fcgi:// incompatibilities

Apache 2.4.10+ will allow the following:

```
<FilesMatch \.php$>
SetHandler proxy:fcgi://localhost:9000
</FilesMatch>
```

This is much easier than using `ProxyPassMatch` (which prevents rewriting and other stuff) and rewrites (which are a bag of hurt because when combined with user-land `.htaccess` rewrites, there's always rewrite loops, prefix breakage etc (I've tried, for weeks).

It's basically the future of using Apache (via `mod_proxy_fcgi`) together with PHP-FPM. It's also available for older versions as a standalone module, very easy to install: https://gist.github.com/progandy/6ed4eeea60f6277c3e39

However, the two bits of code this commit deletes interfere with that. They both cover CGI-only mode and were copied from that SAPI into the FPM source. See e.g. https://bugs.php.net/bug.php?id=47042

The first deleted part mangled `SCRIPT_NAME` if something like

```
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule (.*) index.php/$1 [L]
```

is used (i.e. rewriting to `PATH_INFO`. The second part drops `PATH_INFO` if there was a `REDIRECT_URL` (with CGI mode, `SCRIPT_FILENAME` in Apache is the path to the PHP binary, and `PATH_INFO` contains the name of the script to run).

Clearly, neither applies in the case of FPM, so both are safe to delete.
Merge branch 'pull-request/694' into PHP-5.6

* pull-request/694:
  Fix SetHandler proxy:fcgi:// incompatibilities
adding NEWS entry for the fix for bug #65641