Fix small i18n typos
Merge pull request #4511 from edx/sarina/fix-i18n

Fix small i18n typos
Adds sample student communications (email msgs)
Merge pull request #4400 from edx/ahodges/documentation/DOC591

Adds sample student communications (email msgs)
Add myself to AUTHORS.
Merge pull request #4521 from edx/jeskew/update_authors

Jeskew/update authors