Provide some default skins in Mahara core

[Aaron Wells]

We're in the process of adding a new feature to Mahara, "Page skins", which will allow users to create and use custom themes on individual Pages they create.

For usability purposes, it's important to include some sample skins with Mahara core, so that the "skins" tab isn't empty and useless for new users.

[Aaron Wells (u-aaronw)]

Since skins are now turned off by default, this feature becomes less important. An admin who is activating the skins feature knows what they're getting into.