This patch adds build infrastructure for PHP's OPcache extension.
Compared with the other extension, this is a Zend module and it
need a little workaround during cross-compiling.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Signed-off-by: wuqiong <memccpy@gmail.com>

- split fpm config into main and pool file
- introduced uci config file
- re-worked init script

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Signed-off-by: W. Michael Petullo <mike@flyn.org>