5.2.2 improve abstractions for LTI message validators

This abstracts and DRYs out the code for LTI message validators. There should be no functional changes in this release.

5.2.1 Make "State Not Found" error message more helpful

Changed the ERR_STATE_NOT_FOUND message to be more helpful.

v5.2.0 Add icons to deep links

• Implements icons for Deep Links #64
• Fixes a compatibility issue with PHP 7.4 #67

v5.1.11 - Update another "Missing Registration" error message

This release updates the error message displayed for a missing registration that was missed in release v5.1.9.

v5.1.10 - Only include custom params on a Deep Link if they are set

This fixes a bug where custom params were using the wrong data type if they weren't being set on a Deep Link. #59

v5.1.9 - Update error message for missing registration

This release adds a new LtiMessageLaunch::getMissingRegistrationErrorMsg() function, which dynamically adds the issuer URL and client ID into the error message for a missing registration.

v5.1.8 - Move some constants around related to service requests to fix a bug in logging

This release moves several constants from the LtiServiceConnector to the ServiceRequest object.

It also fixes a bug where we were labeling every request as an auth request in the logs.

v5.1.7 - Add functions for updating lineitems

This release adds a new LtiAssignmentsGradesService::updateLineitem() function, as well as some other changes, which allows lineitems in an LMS to be updated.

5.1.6 Fixed issues with D2L and Blackboard auth

This fixes the issue that was introduced in v5.1.5 which prevented D2L and Blackboard from authenticating users correctly.

v5.1.5 Improve logging on service requests

This adds the ability to log all requests made by the LtiServiceConnector. Previously, service requests were logged, but auth requests were not.