Revert "Merge pull request #105 from code-dot-org/compress_images"

This reverts commit a4c19d23f1c8b06378d6c9a82f4306d3435b3765, reversing
changes made to 901993640a817097a256f1a2337b618f4ca18214.
Merge pull request #117 from code-dot-org/revertImages

Revert "Merge pull request #105 from code-dot-org/compress_images"