Merge branch 'issue-84' into v2

config.go

config_debug.go

db_test.go

mongo/_example/main.go

mysql/Makefile

mysql/_dumps/Makefile

mysql/_example/Makefile

mysql/_example/main.go

mysql/benchmark_test.go

mysql/collection.go

mysql/database.go

mysql/database_test.go

postgresql/Makefile

postgresql/_dumps/Makefile

postgresql/benchmark_test.go

postgresql/collection.go

postgresql/database.go

postgresql/database_test.go

ql/Makefile

ql/_dumps/Makefile