Add option to override metadata in HydroShare

[horsburgh]

If you pick an existing resource in HydroShare and then set the title, or abstract, or funding agency information in the tool, which wins? HydroShare or the tool? Right now, when the tool runs, it will set the metadata in HydroShare to what is in the tool, but there may be some instances where the following happens:

1. The tool creates the resource
2. The user edits the metadata of the resource in HydroShare
3. The user runs the tool again, but doesn't want the tool to overwrite changes they have have made to the metadata in HydroShare.

So, need an option that specifies whether the metadata should be overwritten or not if it already exists.