Hathor tags

Tag field was not shown in hathor. This partial fix solves it even still being required CSS adjustments to see the field right.

I also removed the tag field from the user backend form. It was not used.

Basically for testing we have to ensure that tag is shown in all core content (though bad CSS styles) and metadata options appear and save successfuly:

![test](https://f.cloud.github.com/assets/1119272/405871/4f045e3a-aa1c-11e2-8da9-dda3be194772.png)