build.gradle: Enable eclipse plugin

For Eclim: ./gradlew eclipse, then :ProjectRefresh
build.gradle run: Also use minHeapSize, maxHeapSize

For the sake of my 8GiB RAM notebook that also runs Firefox. ;-)
AnswerGSHook: Add visual separator debug print to make find start of listing easier
ansevid SolrHitsCounter: A trivial search-based evidencer, generating three features

(We will probably prune that to only one or two after some experiments.)