Put a separator before the spreadsheets in the dropdown to make it a bit clearer of the separation.
Changed if not to unless
Formatting.
Migrate .rvmrc to .ruby-version/.ruby-gemset files

.ruby-version/.ruby-gemset are compatible across the other popular Ruby 
environment managers and has been supported in RVM for over 2 years.

Additionally, RVM will automatically setup the gemset, including the
setup/installation of Bundler.

However, it will only show the command to install a Ruby version, it
will not install it automatically. It will also not use bundler to
install everything in the Gemfile.
Merge branch 'master' of git://github.com/MarkUsProject/Markus into issue-636
Formatting and titles fixed.
Fix catching of YAML parsing error in Ruby 2.*

Ruby 2.* uses Psych under the hood for parsing YAML, deprecating Syck.
Now Psych throws a Psych::SyntaxError for parsing error whereas Syck
throws ArgumentError.

This also fixes test failures for #1383.

Tested:
- Ruby 1.9.3-p545
- Ruby 2.1.1-p76
- rake test:units
- rake test:functionals
- rails s
Merge pull request #1441 from zhangsu/fix_yml_error_catching

Fix catching of YAML parsing error in Ruby 2.* Fixes #1383
Merge pull request #1476 from ferrous26/rvmrc-to-ruby-version

Migrate .rvmrc to .ruby-version/.ruby-gemset files
Merge pull request #1464 from arkon94/issue-636

Put a separator before the spreadsheets in the dropdown to make it a bit... Fixes #636.

Also regenerated Gemfile.lock, so this also fixes #1480.
Recompiled Gemfile.lock
Make .ruby-version more palatable to rbenv
Merge pull request #1482 from ferrous26/ruby-version-rbenv

Make .ruby-version more palatable to rbenv
Fix i18n warning about enforcing locale

This gets rid of the warning

```
[deprecated] I18n.enforce_available_locales will default to true in the
future. If you really want to skip validation of your locale you can set
I18n.enforce_available_locales = false to avoid this message.
```

See
http://stackoverflow.com/questions/20361428/rails-i18n-validation-deprecation-warning
Merge pull request #1487 from zhangsu/fix_i18n_warning

Fix i18n warning about enforcing locale
Improve performance of grader-group assignment

Grader assignment to groupings are currently done in nested loops, so
each grader/group combination will issue a query to the database, which
is slow. This can be solved by doing a bulk operation in single queries.

The view also requires some fields that are not eagerly loaded in the
controller, which introduces n+1 query problems.

This patch improves the back end performance of assigning, randomly
assigning and unassigning graders, as well as populating the grader
index page. Assigning graders to criteria is still slow. The front end
is also super slow (it takes a few seconds just to check all the
checkboxes when the number of groups is over 1000!).

This partially solves #1443. The front end JavaScript also has to be
GREATLY optimized to fully resolve that issue.

Tested:
- rake test:units
- rake test:functionals
- local server testing
  - with
    - 2 assignments
    - 3 TAs
    - 1000+ students and groups
    - 2 * 3 * 1000+ = 6000+ TaMembership records
  - wall clock response latency is < 5 second for the optimized
    operations (only counting the back end, the front end can take more
    time than the back end to load)
Fix tests affected by modified parameter format

The query paramters for unassigning graders are changed from
<grouping_id>_<grader_username> to <grouping_id>_<grader_id>, so some
test cases need to be updated.
Add tests for Assignment#criterion_class
Add tests for update_assigned_groups_counts
Add tests for new class methods of Grouping