Translated 28-Limitations_of_Aggregation_Framework-Lecture. Closes #407.
Changes according to feedback from @puentesarrin and @jcarlosgarcia. Refs #407.
Missing change from initial feedback. Refs #407.
Merge pull request #428 from juancarlosfarah/issue-407

Translated 28-Limitations_of_Aggregation_Framework-Lecture. Closes #407.