Cross Direction Layout and updated documentation

- Added methods to enable and disable navigation logics at runtime.
- Added options to get alternative horizontal layout; sections are
stacked vertically and pages are arranged horizontally.
- Added option to reconfigure key bindings for some wireless presenters.
([#15](https://github.com/marcolago/flowtime.js/issues/15))
New Cross Direction Layout and Updated Documentation
New Cross Direction Layout and Updated Documentation

Conflicts:
	examples/custom-fragment-animations/css/custom-fragment.css
	js/flowtime.js