Merge pull request #21 from adlnet/master

Sync!
Update/Restructure 4.1
Reorder 4.1.2 4.1.3 Details before Requirements.  Slight word changes.
Fixed 4.1.4 - Restructured, eliminated confusing headings, Still don't like "Requirements for Metadata"
4.1.5-4.1.8 Just Restructuring
Part 1 Attachments Edit
4.11 and 4.12 restructure/rewrite, includes typo on "applicaton"
Add Description to loose text in 4.0
Update xAPI.md
Update xAPI.md
Update xAPI.md
Update xAPI.md
Update xAPI.md
Merge pull request #325 from andyjohnson/master

Restructure/requirement breakdown of 4.0-4.1.x includes "applicaton" typo