Migration to update STI in existing levels.
Merge pull request #535 from code-dot-org/karel-sti

Migration to update STI in existing levels.
Case insensitive uniqueness constraint on custom built levels.
Test for uniqueness.
Add first artist and maze simplified blocks to level editor
Merge pull request #537 from code-dot-org/fix-validation-case-insensitive

Fix validation case insensitive
Rename old parameter level_type parameter to level.type (merge test conflict)
Update test to use new ajax call instead of standard HTTP POST.
Merge pull request #540 from code-dot-org/fix_level_controller_test

Rename old parameter level_type parameter to level.type (merge test conflict)
Update first block in unit test
Merge pull request #541 from code-dot-org/add_k1_blocks_to_editor

Add some artist and maze simplified blocks to level editor
Merge pull request #539 from code-dot-org/fix-test

Update test to use new ajax call instead of standard HTTP POST.
Automatically built.
Automatically built.
Add simple move blocks with length options
Automatically built.
Merge pull request #542 from code-dot-org/add_k1_blocks_to_editor

Add simple move blocks with length options
howtolink
Merge pull request #544 from code-dot-org/add-howto-link

howtolink
Updated custom levels.