The latest tag for LTI 2.1.1 is https://source.sakaiproject.org/svn/basiclti/tags/basiclti-2.1.1/
The Sakai LTI 2.1.1 release Is really just a bunch of little bug fixes that were encountered as we starting pushing the LORI and auto-tool deployment to the point where it worked smoothly enough for production deployment. There is anot a lot of new UI work - just tidying up.
There is a small data table change to remove "NOT NULL" constraints on several columns in the LTI tables (see BLTI-238). These changes are not essential as higher level logic insures that all the columns in question actually have data (i.e. are never null). If you simply start Sakai with autoDDL=true in your sakai.properties the LTIService will automatically alter missing columns and issue ALTER commands to fix the columns as needed as the version LTI 2.1.1 service starts up for the first time. If you start Sakai with autoDDL=false , it will notice that the tables need to be changed and spam the log ERROR messages indicating the needed SQL statements to bring the tables up to LTI 2.1.1 - the messages look as follows:
If you want to run the conversaion manually so you never have to use autoDDL you can use these conversion scripts
These scripts are in SVN in basiclti/notes These scripts were generated by simply taking a Sakai 2.9.0 database with Basic LTI 2.0.0 and bringing up Basic LTI 2.1.0 with autoDDL=false and extracting the recommended ALTER statements from the log and adding the ALTER statements from BLTI-208.
JIRA Issues Addressed in LTI 2.1.1
There are quite a few fixes that are addressed in 2.1.1