Bug fix exec permissions CentOS - part 1 (#89)

* added CentOS, Fedora, RHEL choices with minimal version check (recommited)

* fixed small typos

* added special option --use-php5-package

* parse options and export new environment variable USE_PHP5_PACKAGE

* added choice between php5* or php7.0* packages (recommited)

* fixed php*-fpm service name and php.ini file path (recommited)

* prepare socket name for nginx to work with php5-fpm or php7.0-fpm (recommited)

* added ppa:ondrej/php5-compat repo

* added dependency ppa:ondrej/php repo and package software-properties-common

* added execute permissions to ./centos/*.sh files