Add Factset which contains a FactsetId and list of partitions

- Add more tests to PartitionSpec
Merge pull request #192 from ambiata/topic/create-in-mem-factset

Add Factset
Fixed the Date literal macro when running Scaladoc
added back classical Scaladoc comments
added a ci profile for the scaladoc
Merge pull request #198 from ambiata/topic/enable-scaladoc

Enable scaladoc and "classical" comments
Remove unused LeanThriftFact
Add ThriftDerserializationBehaviourSpec to demonstrate clear behaviour
Only set ThriftFact seconds if not zero
Add behaviour spec for thrift fact seconds size
Remove ThriftSerialiser.fromBytes as it was doing a deep copy

We can _never_ allow this to be called accidentally
Add extra clearUnsafe test to ThriftDerserializationBehaviourSpec
Use ThriftSerialiser for everything - no exceptions
Remove unused FileSystem import
Change ValueState to handle any ThriftLike value
Extract common setup for priority/namespaced mappers
Changed okCounter var to val
Added type alias MutableFact
Extract PriorityTagDerializer for reducing prioritized thrift values