fix intermittent issue with apache rat

those files are not always considered binary, but they are not directly used by code
Converts task tests from groovy to java
Reduce memory usage in BrooklynGarbageCollector
tidies of Brooklyn node (warnings, logging)
promote snake-yaml dependency and Yamls utility to utils package, and use yaml parsing for map coercion to be much more flexible in terms of string-to-map coercion
remove dead code and tidy warnings in camp code
add an initializer for adding tags, with a test
more tests for BrooklynNode, including test which uses REST API of local instance (and new "SameBrooklynNodeImpl" semi-mock); and adds BrooklynEntityMirror with test
support effector parameters which are maps (@sjcorbett just did this also; now this commit simply adds a test for this)
fix intermittent failing test by ensuring we wait for persistence to complete
This closes #76
This closes #72
This closes #78