Revert "Remove themes and plugins from checked in source"

This reverts commit e6aa9b27f23ff94ce3fa46739255cc6c29dcfe80.
By default, copy the standard wordpress themes into the data directory on setup.  This allows wordpress to reuse the default themes and plugins but still supports users adding their own plugins.

Note! Adding a php/wp-content/plugins or php/wp-content/themes directory will disable the default themes.
Bug 915984 - No longer need to set CREDENTIALS
Merge pull request #28 from smarterclayton/master

Bug 915415 - Make plugins/themes default to wordpress defaults