renamed markdown attributes for clarity and consistency: data-vertical -> data-separator-vertical, data-notes -> data-separator-notes

The previous criteria "verticalSlideCount > 0" would result
in verticalOffset being NaN when verticalSlideCount == 1.

This would cause dom.background.style.backgroundPosition to
be set to something like "123px NaNpx", ultimately preventing
the parallax effect to play (silently failing so far).

Correction of a small error

For the Moon and Solarized themes they had .css appended to them which was causing them to not come up.

- upgrade grunt-contrib-connect to ~0.5.0
- configure connect and watch plugin

fix theme links in demo

For the Moon and Solarized themes they had .css appended to them which was causing them to not come up.