FIrst commit.
Add scrolling map. Fix player position
Add control instructions.
Merge pull request #1 from oscarhong/camera

Add scrolling map. Fix player position
Basic map system implemented
added improved performance
add map background
Added camera movements, most of the basic map system.

Changed map drawing to be on the diagonal instead of stacked.  This is
so that map coordinates are much more intuitive for humans, and it is
less painful to work with.

Camera movements have been coded to adjust based on the player's facing
position and speed.  Further refining and tweaking is expected.

Added a debug flag, so that all the drawing stuff should disappear if
debugMode is turned off.

Things to work on in the future on my part: add a canvas pool, figure
out the limit to the number of HTML elements, normalize the world X and
Y coordinates with the individual TileMap entities, dynamic map
generation (basic), dynamic map generation (advanced)
Merge remote-tracking branch 'upstream/master'
Merge from upstream
Fixed player sprite not respecting Y axis positioning on camera.
Hugely expanded map

Huge map system that divides the world into quadrants.  Map resources
are not loaded until the player is nearby.

Things to work on:
-- Wrapping in X and Y
-- Normalize the islands so that they "snap" to the tile grid
-- Add collision to the islands
-- Draw sprites appropriately if they're behind some land
-- Implement minimap
Add random moving enemy
Add height differece indicator for enemy
Enemy stop moving if too far form player. Add debug message for one enemy
Add fire with spacebar. Fix game engine bugs
Visual glitch fixes, added items

Added collectable items. These can be added to an island's local map by
simply adding the item using TileMap.addItem(), and the local map
coordinates.  Specific islands can be added anywhere on the global map
using Map.addIsland()

Items collected currently do not influence the player state, but they
stay gone if collected.  They load and unload just as their parent
island maps do.
merge upstream/map
Fix bullet after merging map
Merge branch 'master' into gh-pages