This closes #113
prototype of service_up being derived from service_not_up_indicators
add WhenFunctions which allows `Functionals.when(false).value("F")` approach to building up functions
add a new "updatingMap" enricher which helps when multiple enrichers contribute to a map, and use it for the new chaining of service_up behaviour
minor test utils fixes, including `assertThat`
jsgui: New policies are displayed immediately
This closes #126
Support for adding YAML defined policies to the catalog.

OSGi support included.
Unify entity and policy detail views.
Fix typo in GitHub example url for NodeJsTodoApplication
refactor Enrichers.builder() types to give correct generics for published sensor
add support for suppressing duplicates in enrichers, defaulting false for most, but true for UpdatingMap; and in Enrichers.builder() use better superclasses to support tags, uniqueTags
simple cleaned up illustration of service_up from not_up computation
a bunch more service-up checks (WIP)
fix enricher type test with suppress duplicates
rename WhenFunctions class to IfFunctions, and tidies/cleanups there and in enrichers
add SERVICE_PROBLEMS and enrichers in ServiceStateLogic to compute state from that.
add enrichers to populate PROBLEMS and NOT_UP_INDICATORS from children and members: this removes a lot of ad hoc service-up computations; some quorum up logic e.g. for mongo, have changed, but in those cases the previous logic was quite hokey in any case. (to properly support QUORUM_SIZE we should have a key, or use the UP_QUORUM_CHECK config).
also tweak the recent workaround when AbstractEntity.add{Enricher,Policy} detects a duplicate, we now take the more recent one rather than the older one; this allows us to replace them in a principled fashion when using unique tags.
some notes on tidying the REST API
default children/members enrichers for service_up and service_problems ignores entities that report null as well as those that don't report; this can be overridden with IGNORE_{NULL,TRANSITIONING} config keys.
and the load balancing policy defaults not to blocking service up simply because children/members are not present. misc other tidies around policies.
rewrite of ServiceFailureDetector -- part of what it did before is now done by ServiceStateLogic of course,
so now this extends that, and provides options for emitting notifications of ENTITY_FAILED, ENTITY_RECOVERED, as well as suppressing ON_FIRE