Merge pull request #213 from ljwolford/bugs

refactored retrieve_statement and req_process
trying to make gets faster
fixing stored ordering
still trying to fix order of statments
small tweaks to ret stmts
Merge pull request #215 from creighton/improve

speeding up get statements
speeding up the my statements ui
Merge pull request #217 from creighton/improve

speeding up the my statements ui
working on the document apis
working on the document apis
fixing tests
fixing state post
Merge pull request #218 from creighton/improve

Improve
fixing case where id list is empty
Merge pull request #219 from creighton/improve

fixing case where id list is empty
okMerge branch 'master' of https://github.com/adlnet/ADL_LRS into bugs
added check score types in validator