Implements hashCode if equals is defined.

* src/core/java/com/dataiku/dip/partitioning/TimeDimension.java: Here.
Add with setters. Delete toPrettyString (duplicate to id).

* src/core/java/com/dataiku/dip/partitioning/TimeDimensionValue.java:
  Here.
long-list: Hidde internal stuff.

* src/core/java/com/dataiku/dip/utils/LongList.java: Hide getAllData.