Add information about activities to the wu details meta service

Add some extra information including

• whether an attribute is a list, or can have multiple values.
• A list of all activities and their descriptions, possibly whether they are sinks or sources.

For the second use you should use the range TAKnone..TAKlast and getActivityText(), isActivitySource(), isActivitySink().

The functions might need to move to a different dll if there is a problem linking thorcommon.