Will checkouts using this repository be persisted so they can
be refreshed in the future? This property is of concern to SCMs
like Perforce and Clearcase where the server must track where a
user checks out to. If false, the server entry (clientspec in Perforce
terminology) will be deleted after the checkout is complete so the
files will not be able to be updated.
This setting can be overriden by using the system property
"maven.scm.persistcheckout" to true.
The default is false. See SCM-113 for more detail.