Remove deprecations + Some cleanup

[offirgolan]

Resolves #100

• Renamed lt-column-resize to lt-column-resizer
• Fixed deprecation warning caused by checking fixedHeader & fixedFooter twice on the same render
• Fixed deprecation caused by multiple renders in lt-infinity by forcing each observer call to execute on the afterRender queue of the run loop

[taras]

It's unfortunate that we need to do all of this hackary with the runloop to get this to work properly. Hopefully we'll find another approach in the future.

[offirgolan]

@taras I agree but I think the current implementation is rather clean and self explanatory. Maybe in the future we can think of a better way to do the whole sharedOptions stuff