Merge pull request #95 from nanan9177/master

Turtle Free Play Message Update
Fixed the color picker on page http://localhost:3000/s/1/level/37?level=4_2.
Updated required block number on Maze 2 Level 17.
Updated required block number on Maze 2 Level 18.
Fixed the rendering of obstacle.
Added back Turtle 1 Level 10's toolbox.
Corrected Turtle's play level continue button.
Merge pull request #96 from nanan9177/fix_color_picker

Commits that fix some bugs in Maze and Turtle
Fixes start blocks and provides better XML parsing errors.
Merge pull request #97 from brandonbloom/xml-errors

Fixes start blocks and provides better XML parsing errors.
Fixed most jshint warnings
Updated Maze 2 Level 2 so the mouse is facing south.
Merge pull request #99 from nanan9177/maze_test

Updated Maze 2 Level 2 so the mouse is facing south.
Merge pull request #98 from brandonbloom/jshint

Fixed most jshint warnings
Changed the empty block message.
Merge pull request #101 from nanan9177/maze_test

Changed the empty block message.
Removed Karel finish markers.
Merge pull request #102 from nanan9177/maze_test

Removed Karel finish markers.
Switched namespace of Blocks from Language to Blocks to accord with Blockly core changes.
Added blockly_debug, a concatted but unminified version of blockly.
Copied new dependencies from blockly-core.
en.js replaces en_compressed.js.