Minor Changes

Cleaned up the code in DDCommandBase a little.
Changes to Commands

1. Fixed some warnings in the affected commands.
2. Removed checks for whether a command is running on the server or
client side. We have performed those checks inconsistently throughout
our commands without problems. I assume that they must be running on the
server side only. If I'm wrong, we can add a check to DDCommandBase.
3. Minor punctuation change in DDCommandResult