Use static strings instead of magic ones in APIHelpers.java
Changed log_tag back to canvas-api

This won't be an issue anymore once we update local repos
Course Moderation APIs (Updating course settings)

Add Various Date helpers.
Add Various Synchronous APIs.
Add Section API.
Merge pull request #5 from joshruesch/master

Course Moderation APIs (Updating course settings)

Add Various Date helpers.
Add Various Synchronous APIs.
Add Section API.