UI changes to learn.code.org root and sign-in pages.  Also header's link to sign up goes to root.
First stab at builder.
Add create custom to levels
We can succesfully build an artist level, and return a link to it.
Move row insertion from migration to seed.
You can create a level, get a link, a use the link.
Use 'custom' blockly level instead of 'builder'.
Use constants for readability.

Use active record relation to improve readability.
Integrate all of Chris' feedback except for auth stuff.
Move seed:all tasks to be run only on primary machine.
Mereged from master.
Merge pull request #273 from nanan9177/deployment

Move seed:all tasks to be run only on primary machine.
Add the hint access column in the user page.
Merge pull request #274 from nanan9177/blockly_fix

Bug fix.
Merge pull request #275 from nanan9177/blockly_fix

Moving the number of attempts out of the search.
Adding cd to directory in seed task.
Merge pull request #276 from nanan9177/deployment

Adding cd to directory in seed task.
Fix.
Merge pull request #277 from nanan9177/deployment

Fix.
Fix up before filters and auth stuff.