Merge pull request #6 from saebyn/master

Adds LTI-launch post type to allow for pre-configured launches.
Merge pull request #7 from saebyn/master

Bug fixes and new features
Merge pull request #8 from saebyn/master

Applies from name changes and fixes the iframe.
Merge pull request #11 from saebyn/master

Fixes #10 - Adds launch.js to admin scripts.
Merge pull request #13 from saebyn/master

Fixes #12 - incorrect property name for the user's ID.
Fixes problems with GET parameters in launch URLs and improperly escaped URLs.