Handles discovery and valuation of a
boolean object property, of the
form public boolean is when executed.
We do this separately as to preserve the current
quasi-broken semantics of get
get< flip 1st char> get("property") and now followed
by is author: Geir Magnusson Jr. version: $Id: BooleanPropertyExecutor.java 463298 2006-10-12 16:10:32Z henning $