Allow Eclilpse debugger to inspect more UIMA internals

While debugging something, I got frustrated by the value inspector of Eclipse saying something like ... exception.. instead of the value. The internet suggested that hashCode throwing exceptions might be the cause. I found several of the internal UIMA objects had hashCode set to throw unsupportedException - and changed those to some reasonable hash code, it allowed the Eclipse debugger to show the values of these objects. Fixup some of these and improve the toString methods, for better debugging capability.