AbstractEntityFilter: testability

Improves testability by introducing a EntityFilterContext
interface.
Merge pull request #13 in WAY/way-ui from moe_16_entity_filter to master

* commit 'dad6f7adfbbeabd290e64fb0fa6349c0075ed829':
  AbstractEntityFilter: testability
[maven-release-plugin] prepare release way-ui-1.5.4