Style Cleanup

Added js strict mode.
Changed from inconsistent mix of tabs and spaces to spaces.
Used consistent spacing between assignment and commas.
Added missing semicolons.
Added missing radix on parseInt operations.
Consistently using single quoted strings.
Removed unused global variable from app.js.
Added how to run in README. Cleaned up git-flavored markdown.
Fully Jade-ified layout.jade.
Jade-ified main.jade to DRY up the layout.
Replaced class and id attributes with short Jade values.
The id for post should be a class because it repeats.
Removed Execute property from layout (Why was it there?)
Added explicit css padding instead of relying on spacing.