ISPN-800 Tests for library mode

* also formatting changes in core/pom.xml
ISPN-800 The osgi test bundle should export the test packages as they might contain classes which need to be loaded by ispn.
ISPN-4097 Add SKIP_CACHE_LOAD flag for Hot Rod
ISPN-3838 L1 entry added by ST when already invalidated

* Removed L1OnRehash as it is broken with a concurrent modification
fixed compilation issue
ISPN-4241 Distexec cannot clone tasks for distributed executions in Karaf

Changed the OSGi headers for infinispan-commons to include DynamicImport-Package=* as the marshaller needs to be able to load classes from client bundles.
ISPN-4261 Clean up Karaf's features files
ISPN-4137 Transaction executed multiple times due to forwarded CommitCommand

* Remove the "skipTransactionCompletedCheck" transaction flag.
* Only mark the transaction as completed after running the prepare from
  state transfer (if needed).
* Do not try to roll back if commit fails and recovery is enabled.
ISPN-4137 Transaction executed multiple times due to forwarded CommitCommand

Make rollback commands synchronous, but without sending a TxCompletionCommand.