Add javadoc for the query dsl
ISPN-3755 Add more detailed description of the filtering operators supported by the new query DSL
ISPN-3772 Reduce marshalling payload sizes

* Unless compatibility and query mode are enabled, do not use
Flag.OPERATION_x.
* Flags, which are shipped in EnumSet instances, are now marshalled
using Externalizers, leading to a reduction in size as a result of
not writing class information.
* Except for primitive types, arrays can be shrinked by using
exterternalizers for those arrays more commonly shiped. This results
in array type information not being written to the payload.
* Add Arrays$ArrayList to the types covered by the ListExternalizer,
which it now covers for all list implementations.

Flags also used in query
Ignore Checkstyle metadata produced by the Eclipse plugins