Second batch of ORA UI fixes:

- Change wording when done with peer grading ("evals" -> "assessments")
- Added ICE legend item for comment syntax
- Added conditionals to display human readable 'grader_type' to alleviate confusion
- Rename 'Show/Hide Prompt' to 'Show/Hide Question'
- Reworded grading flags
- Make ICE grading container larger to more easily allow users to read and edit larger texts
- Adjusted lots of text and word choices to make them more user friendly
- Disable previous arrow on first grader feedback and next arrow on last grader feedback
- hide ORA instructions and ICE legend when calibrating so students don't feel like they need to write feedback

Changes after comments:

- Renamed instructions element and fixed casing issue
- Renamed legend class to ice-legend
- Changing condition from != to >= to not only fix incorrect one but also catch possible weirdness
- Grammar fix in a message
- Removing grader_type conditional in HTMl to give way to the one in python
- Moving ice feedback area height styling to CSS file

More changes:

- Update ICE version
- Modifying test to reflect code change
- Adding ICE undo feature
Last Changes before Merge

- Change variable name to make it more clear
Merge pull request #1066 from edx/giulio/ORA-fixes-2

Second batch of ORA UI fixes (with an ICE bonus!)