CXX-163 Create integration target
CXX-158 Add GridFS integration tests
CXX-159 Add SASL client auth integration test
minor: exampleSourceMap formatiing
minor: scoped_db_conn_test ordering
CXX-163 improve integration target in various ways

Move integration tests and associated files under unittest directory
Move client_test_main and integration_test_main under unittest directory
CXX-163 actually use port parameter and renamings
CXX-163 add licenses
CXX-163 move and rename integrationTestParams