Again trying to complete SQLDroidDatabaseMetaData

I replaced basically the entire class *SQLDroidDatabaseMetaData* with its corresponding class found in *org.sqlite.MetaData* (downloaded from https://bitbucket.org/xerial/sqlite-jdbc/downloads - file sqlite-jdbc-3.7.15-m1-sources). The source project (on bitbucket.org) is licenced under the Apache Licence, hence this should be no problem.

This time, I replaced more than a few methods - I replaced the entire class and re-added a few missing methods (=> newer JDBC version).