Make sure that SomePropertySerializer only serializes SomeProperty.
Change greater than comparator serialization from > to >> .

This will avoid ambiguity as in Semantic MediaWiki > is "greater than or equal" by default, but "greater
than" if $smwStrictComparators = true; .
Add the rest of the comparators to ValueDescriptionSerializer.
Test what ValueDescriptionSerializer accepts more strictly.
Make sure that AnyValueSerializer only serializes AnyValue.
Correct namespace for tests from Formatter to Serializers.
Add Factory::createDescriptionSerializer().
Add incomplete tests for partially done Descriptions.
Make SomePropertySerializer work with any sub Description.
Add ConjunctionSerializer.
Add DescriptionCollectionSerializer.
Add DisjunctionSerializer.
Add Conjunction and Disjunction Description Serializer to Factory.
Add QuerySerializer.
Add a few test thats still need to implemented.
Add QueryOptionsSerializer.
Implement serializing options in QuerySerializer.
Merge pull request #1 from JanZerebecki/master

further implementation