CreateCommand -- Rename "--no-db" to "--skip-db" and "--no-url" to "--skip-url"

There's a subtle distinction -- when forcing (overwriting/recreating), the
"--skip-db" option will do nothing (leave the DB alone); the "--no-db"
option suggests that the DB should not exist.
Merge pull request #4 from totten/master-skip-option

CreateCommand -- Rename "--no-db" to "--skip-db" and "--no-url" to "--skip-url"