Added comment to describe why using SQLiteDabase.beginTransaction() for outer transaction and SAVEPOINT...RELEASE for inner transaction.
Added comment to describe why using SQLiteDabase.beginTransaction() for outer transaction and SAVEPOINT...RELEASE for inner transaction.

Spotme/couchbase-lite-java-core,mariosotil/couchbase-lite-java-core,gotmyjobs/couchbase-lite-java-core,couchbase/couchbase-lite-java-core,netsense-sas/couchbase-lite-java-core,mariosotil/couchbase-lite-java-core,mariosotil/couchbase-lite-java-core,4u7/couchbase-lite-java-core