Update Rakefile to ease building all drivers and adapters
Update Rakefile to ease building all drivers and adapters

- all namespace now operates on drivers and adapters
- new drivers namespace operates only on drivers
- new adapters namespace operates only on adapters

keeguon/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter