In case anyone is interested: To load the APL code, after a git checkout, I would type
]load C:\Devt\breadboarder\src\apl\*
In versions <17.0 which is as yet unreleased, you will need to do that twice because a few of the source files will fail to load due to missing base classes. The second time, the base classses are define (in v17.0 we allow classes to be fixed even if dependencies are missing).