Change to statement id description

We now say elsewhere that statement ID SHOULD be set by the activity provider
Section 4 headings to verb
Merge pull request #126 from garemoko/section4headings

headings as far as verb (inclusive)
heading changes down to the end of context
Merge pull request #127 from garemoko/objectheadings

heading changes down to the end of context
headings down to end of section 4
Merge pull request #128 from garemoko/headingsTimestamp

more headings down to end of section 4
sections 5 and 6 headings
Merge pull request #129 from garemoko/headings5

sections 5 and 6 headings
Add headings list to readme
Merge pull request #19 from adlnet/master

get adlnet master
Fixed a couple of formatting problems I created
Merge pull request #20 from adlnet/master

pull in new commits from adl master
Linked activity type to note about defining new verbs.
added Appendix E: Converting Statements to 1.0
Added encouragement to re-use all types of identifier URI
Updated hash counts 

Formatting change for consistency
Fixed typos
Merge pull request #132 from garemoko/notes

Fixed two formatting issues
Merge pull request #134 from garemoko/activityType

re-using URI identifiers