[BUG] Installing a package leaves stale .xar in /db/system/repo

[adamretter]

If you upload and install an EXPath using the Dashboard's package manager, then after the installation is complete. There is a copy of the EXPath package XAR file left in /db/system/repo. This XAR file should be removed after the installation succeeds or fails.

The same does not happen when installing packages via autodeploy

[wolfgangmm]

Note: while the XARs can be removed, the few subcollections of /db/system/repo should stay as they are relevant for reconstructing the repo after a restore.