Merge pull request #1 from adlnet/master

get changes back from master
In 3.0 Definitions, Make the Definitions linkable
Merge pull request #2 from adlnet/master

pull from master
Merge pull request #3 from aaronesilvers/master

getting changes from Aaron
Modified 'registration' definition and moved some content to 4.1.6

Removed "Note: activity providers are cautioned against reporting 
registration other than when assigned by an LRS. An LRS that assigns registrations is 
likely to reject statements containing unassigned registration IDs." as accepted practice encourages more broader use of registration
Addded definition for 'immutable'
tidy spacing in examples
Moved most example statements from 4.1 to Appendix D

Included link to appendix D in section 4.1
Further example statements now can be added to appendix D for greater illustration without bloating the main body of the specification. 
Add "type" column to tables up to 4.1.5

Tables from 4.1.5 onwards to be amended later. 
adding additional "type" column
fixing last commit
Added some additional type column

note: This commit is half way through a table which may lead to some
display issues.
amended registration as discussed

also added more types. 
Merge pull request #9 from garemoko/master

re-working registration definition