Enable blocks to be embedded in hints.  This needs cleanup.
Made iframe transparent, per Brian's suggestion.
Removed testing code from maze.js.
Added comment. Replaced trimRight() with trim() for IE9.
Merge branch 'master' into hints
Minor style changes.
Improved comment.
Improved comment per Nan's suggestion.
Merge pull request #661 from code-dot-org/hints

Added ability to embed blocks in hints provided through dashboard
[finishes #70102748]: improve feedback blocks
Merge pull request #664 from code-dot-org/studio_feedback_blocks

[finishes #70102748]: improve feedback blocks
[#70374808] only preventDefault when running - allows touch scrolling before running
Merge pull request #665 from code-dot-org/tweak_hammer_gestures

[#70374808] only preventDefault when running - allows touch scrolling before running
fix for iframe insertion
Merge pull request #666 from code-dot-org/fix_feedback_block_margins

fix for iframe insertion
remove extra BlocklyApps.
[finishes #70782706] add arrangeStartBlocks()
K1 studio/flappy changes:
- Add new flappy k1 enter obstacle icon
- Add new When Run icon to flappy and studio
- Add new k1 speed dropdown to flappy, programatically resized to closer match flappy block sizes
Merge pull request #668 from code-dot-org/studio_block_alignment

[finishes #70782706] add arrangeStartBlocks()
Add k1 score block to flappy. Resize score graphic to 75%.