What's the purpose of the new custom library types (e.g. General, Scripting, Connector)? Are they simply for organizational purposes?
The types are indicative of the place on the atom the JAR file(s) that are referenced by the Custom Library component will be deployed to; these are the same locations that a user would previously need to manually place the JAR file(s) to attain specific functionality.
For example, if you need a specific driver for your database connector, you would choose Connector (Database) as the type and include the JAR file that you previously uploaded to your account that contains the driver as part of the Custom Library component; then when the component is deployed, the driver JAR file will be downloaded into the /userlib/database directory of your atom.
For more information about using the Custom Library component, I would recommend Custom Library components which describes the differences of the types.
Retrieving data ...