Updated Diff Web API command.

Made it so it won't crash if the change list is very large.
Now supports classic "diff" as well as just geometry changes.
Added all option to featureDiff so that i can get all attributes for a feature through the web-api.

Also fixed Diff to return the feature path instead of the id.
Merge pull request #243 from jdgarrett/webdiff

Updated Diff Web API command.