Stacks demo
Corrected headline
stacks: tweak draft documentation.
stacks: Load correct CSS file in demo
Stacks: rough start of implementation.
Stacks: update anchor classes.
Update documentation.
Move hide-or-remove from depends to utils

This allows reuse in other patterns.
Stacks: enable animation.
Stacks: expose easing option.
Documentation tweaks
Merge pull request #350 from Patternslib/pat-stacks

Pattern 'Stacks'