- add postfixadmin-upstream-fixes-r1802-1817.diff:
fix escaping in gen_show_status() and double escaping in list.php
(http://sourceforge.net/p/postfixadmin/bugs/356/)

- several fixes for the Fedora and CentOS build:
- don't scan scripts in the ADDITIONS directory to avoid adding excessive
dependencies
- use centos_ver instead of centos_version (which isn't available in CentOS 7)
- change docroot to /var/www/html
- change apache group to "apache"