Simplify visualization panels with RevealNode

We can remove all node b.s. and the ListenableFuture bits.
Merge pull request #81 from physion/entity-selection

Entity selection
prepare release 2.1.23
update to snapshot version 2.1.24-SNAPSHOT
Fixes UI display of all search results

Some results are null, so we need to check for it.
prepare release 2.1.24
update to snapshot version 2.1.25-SNAPSHOT