Using webworkers #18, #19

Web Workers is a simple means for web content to run scripts in background threads. From "Using Web Workers" on Mozilla's documentation.

Because I was previously working on the grid system, now I've implemented path finding for NPCs. This is nothing more than basic A* with a couple of tweaks - most important being the ability of cutting corners or not.

I used easystar JavaScript library which is "an asynchronous A* pathfinding API written in Javascript". I put that into a webworker and every time I need to compute a value I just pass the webworker start location, end location and the grid's array.

JavaScript is single threaded but Web workers work on different thread so they will not block the UI.