The subproject "jackrabbit-api" has been moved to Oak as per
OAK-8339. After the next stable release of Oak (1.16.0), we'll
a) remove the jackrabbit-api project from Jackrabbit, and
b) reference oak-jackrabbit-api instead.
Note that this applies to trunk only; the first stable Jackrabbit release affected will be 2.20.0 - maintenance branches will not change.