Deprecate -runCommandWithDictionary

For runCommand to work, the document needs to contain the command in the first key. In other words, it needs to be in order. Despite that order is clearly defined in BSON, it's not preserved by NSDictionary nor by Swift's dictionary.

Intsead, call one of the following:
- `-runCommandWithName:value:arguments:onDatabaseName:`
- `-runCommandWithOrderedDictionary:onDatabaseName:error:`

Fixes #16