Bug 1052960 - [Calendar] Day View: update it to use same logic as the 5-day week view r=gaye

1054 **deletions**, 308 additions!!!
it's a common convention to say that `md` is some sort of namespace. in this case `md == "multi day"`

in fact I replaced it with a double underscore to match the [BEM naming convention](http://csswizardry.com/2013/01/mindbemding-getting-your-head-round-bem-syntax/)

the names `all-day`, `sticky`, `event`, `event-title`, `location` are very likely to appear elsewhere on our codebase.. so it's better to namespace it to avoid conflicts.

it reduces the CSS specificity and also makes the code easier to `grep`.