Activate read/write behaviour in activateAccount

* Added a @Transactional annotation to AccountService#activateAccount
with the "readOnly" property set to "true" so that the activation changes
are persisted to the DB
Delete token *after* account update

* The password reset and account activation tokens
should only be deleted after the changes to the account have
been persisted to the DB
Save runtime config in solr.xml

* Completely load the "swiftriver" core on startup

* Explicitly set the data directory for the "swiftriver" core. This directory
is relative to the "instanceDir"