Fixes menu too long bug, adds collapsible examples.

This is the result of running `grunt examples` to update the html examples and also adding links to the new `collapsible` template styles on the `README.md`.

You can preview the end result of these examples via the following URLs:

http://htmlpreview.github.io/?https://raw.githubusercontent.com/chesleybrown/aglio/blob/collapsible-readme/examples/default-collapsible.html

http://htmlpreview.github.io/?https://raw.githubusercontent.com/chesleybrown/aglio/blob/collapsible-readme/examples/flatly-collapsible.html

http://htmlpreview.github.io/?https://raw.githubusercontent.com/chesleybrown/aglio/blob/collapsible-readme/examples/slate-collapsible.html

http://htmlpreview.github.io/?https://raw.githubusercontent.com/chesleybrown/aglio/blob/collapsible-readme/examples/cyborg-collapsible.html

NOTE: This also includes a bug fix I noticed for the menu being too long for `flatly`, `slate` and `cyborg`. See 61ccb21.