Setup Content Updating
- Didn't do this before, but now it's setup: content will be updated on the DHT if a StoreContentMessage is sent with a newer version of the content

GetParameter
- Updated the GetParameter so that it can be constructed from a KadContent object or a StorageEntryMetadata object
- Move it to the DHT package

Others
- Added a few methods to StorageEntryMetadata, StorageEntryManager& DHT to simplify conversions between KadContent, GetParameter & StorageEntryMetadata

Tests
- Written a test to check content updating