Add text and user defined classes/tags

[ShahNafis]

I was wondering instead of having predefined classes and tags if it is possible to add user-defined classes/tags or text. For example, let's say there is an image of a cat, using a bounding box the user would select the left eye, add a class for eye a tag for color and add a description saying something like "This is the left eye of the cat".

Perhaps even have it where just text could be used.

[seveibar]

Custom text, it's a good idea!

[seveibar]

This is somewhat possible using the custom label entry thing #28, but I think building it in would be nice. We might be expanding to have a more complex data entry system allowed for the label dialog in the near future