Do some miscellaneous code cleanup.

Review Request #7906 — Created Jan. 25, 2016 and submitted — Latest diff uploaded

Information

student-sonar
master
1ff66bc...

Reviewers

This primarily is just switching out let for const where we can, but
there's also some formatting changes and a couple places where promises could
be used more effectively.

Flipped through all the affected pages and saw that things still worked as
expected.