Auto-determine FreeBSD package prefix from version

If the php version has been set in globals, use it to determine the
default package prefix on FreeBSD.
This should be a compatible change, since the package prefix can still
be overridden, and has to match the selected version anyway.

manifests/globals.pp

@@ -144,6 +144,14 @@
       }
     }
     'FreeBSD': {
+      case $globals_php_version {
+        /^(\d)\.(\d)$/: {
+          $package_prefix = "php${1}${2}-"
+        }
+        default: {
+          $package_prefix = "php56-"
+        }
+      }
       $default_config_root  = '/usr/local/etc'
       $default_fpm_pid_file = '/var/run/php-fpm.pid'
       $fpm_service_name     = undef

manifests/params.pp

@@ -178,7 +178,7 @@
       $fpm_group               = 'www'
       $embedded_package_suffix = 'embed'
       $embedded_inifile        = "${config_root}/php-embed.ini"
-      $package_prefix          = 'php56-'
+      $package_prefix          = $php::globals::package_prefix
       $compiler_packages       = ['gcc']
       $manage_repos            = false
       $root_group              = 'wheel'