Use mariadb as default to be debian compliant with

https://wiki.debian.org/Teams/MySQL/virtual-mysql-server

build/debian/control

@@ -26,11 +26,11 @@ Depends: libapache2-mod-php5 | libapache2-mod-php5filter | php5-cgi | php5-fpm |
 # Misc dependencies
 #    fonts-dejavu-core | ttf-dejavu-core,
     xdg-utils,
-    virtual-mysql-client,
+    mariadb-client | virtual-mysql-client,
     ${misc:Depends},
     ${perl:Depends}
 Recommends: apache2 | lighttpd | httpd,
-    virtual-mysql-server
+    mariadb-server | virtual-mysql-server
 Suggests: www-browser, php5-geoip
 Description: Web based software to manage a company or foundation
  Dolibarr ERP & CRM is an easy to use open source/free software package for