New feature for lti module.

Add ability to display LTI module in a new
window. Iframe will be still supported.

Fix python test
Update acceptance tests
Fix in acceptance tests, they are stable now
Fix Acceptance tests.
Adding Jasmine tests for LTI.
Fixing Jasmine tests. Adding the rest of Jasmine tests.
Updated Jasmine tests as per Anton's and Alex's suggestions.
Oops. Forgot to delete one more template.
Updating LTI template.
Add display_name to lti template
Adding fix for failing Python unit test.
Addressing comments by auraz and singingwolfboy.

Removed JS check for empty url and default url. In template added
i18n support for several strings.
Fixing template bug.
Added back check in JS for empty or default URL.
styling for LTI in a new window block
Minor styling tweaks. Added Changelog entry.

Made it so that the link and the text are on the same level, and in the
center of the block.
Fix attribute target.