initial commit of TilesCore.js
refactored _storeTile() to TilesCore
refactored parseGetTiledInfo to TilesCore
Merge branch 'master' into consolidate-tile-core
refactored getTilePolygons to TilesCore
refactored loadFromFile() into TilesCore
refactored estimateTileSize() into TilesCore
refactored saveToFile() to TilesCore
refactored prepareForOffline() to TilesCore
refactored _getTilesUrl() to TilesCore
added code comments
Merge pull request #225 from andygup/consolidate-tile-core

Closes #221