Pull global javascript variables for last AJAX response into a single hash
 - Clarify lastAjax -> lastAjaxRequest
Add helpers for unplugged / multi / match game types
Skip unplugged script levels during "next" progression
- Pull script level success AJAX response controller code out of model and into constituent helpers
- Refactor for single points of truth for various script level progression logic
- Add helper for first level in script
- Add helper for skipping invalid script levels
- Pull HoC finish URL out into a helper
- Note: WIP since doesn't account for ignoring unfinished unplugged levels during User progress resume
Add pointer to relevant method
Remove is_ from is_.(match|multi|unplugged)? methods
s/next_untried_level/next_unpassed_level
Remove unnecessary boolean helper
Adding untranslated strings from teacher dashboard
fixed embedded in javascript translations
Clarify method
remove 'old' 'new' teacher dashboard stuff from dashboard -- skeleton of section login
section log in page
put together strings that should not be separated
Merge pull request #1081 from code-dot-org/rip-out-dashboard-new-teacher-ui

New section login pages
use alert instead of error so it actually shows up
Merge pull request #1082 from code-dot-org/rip-out-dashboard-new-teacher-ui

use alert instead of error so it actually shows up
resolved merge conflicts
Fix custom level import for changing type attribute.
Move helpers into script_levels_helper
- Account for non-progression levels (i.e., unplugged) in next progression for user
- Add test for HoC -> 20hr post-completion redirect
Fix /hoc/20
- Add test covering /hoc/20 loading
- Move current_user reference out of model and in to controller helper