Merge pull request #287 from andyjohnson/master

Editted/Added 2 Definitions
Rationale was really a requirement, so moved it and added new rationale
Merge pull request #290 from andyjohnson/master

Section 2 Edits from Heather (one adds to table of contents)
Merge pull request #288 from bscSCORM/security

Rationale was really a requirement, so moved it and added new rationale
Merge pull request #14 from adlnet/master

Sync up!