Replace FasterCSV with CSV in lib/benchmarking
vagrant can now see Markus folder on home machine
Avoid n+1 queries when downloading all submissions

Lots of queries are redundant in the logic of downloading all
submissions and can be avoided by eagerly loading the associations.

Tested:
- rspec
- rake test:units
- rake test:functionals
Merge branch 'replace-fastercsv-benchmarking' of https://github.com/oneohtrix/Markus into replace-fastercsv-benchmarking
Fixed indentation for Hound
Merge pull request #1648 from zhangsu/download_all_submission_performance

Avoid n+1 queries when downloading all submissions
Merge pull request #1626 from munrocape/vagrant-ide

vagrant can now see Markus folder on home machine