Proposal for a 2.0.0 selector naming scheme

[jbranchaud]

I am thinking about using cap as a prefix to avoid conflicts with other css and then the following set of options:

• cap-bottom - caption positioned inside the image at the bottom
• cap-top - caption positioned inside the image at the top
• cap-under - caption positioned outside the image, right under it
• cap-above - caption positioned outside the image, right above it
• cap-over - caption overlayed on the entire image

This covers existing options (embed, embed-top, overlay) and also gives two more options that avoid obscuring the image by placing it above or under the image.