Hey,
The 3 components in Wikibase.git (Repo, Client and Lib) are the only ones left with manually maintained autoload classmaps. Time to get rid of them!
The effect of these changes is that one has to trigger the rebuild of the classmaps whenever a class is added or moved. This can be done by running "composer update". This is also the case when doing a git pull that brings such changes.
Ultimately it would be good to have the code in Wikibase.git be properly split and made PSR-0 compliant. If we use PSR-0 based loading, we will not have to deal with any classmap hassle.