Support for lists of values to match in searches #532

Especially in the API, but also in regular search, it would be useful to be able support a list of values to search on with an ' OR ' separating each. For example, for a list of occurrenceIDs, one might want to do something like this:

http://api.vertnet-portal.appspot.com/api/search?q={%22q%22:%22occurrenceid:in(7108667e-1483-4d04-b204-6a44a73a5219,urn:catalog:CRCM:Mammals:13-127)%22}