Bug 167450 [DataBinding] Get rid of bind support factory magic
I finally realized that we don't need that other magic factory. I'll move fillBindSpecDefaults() and the methods it calls (createConverter, createValidator etc) to a new class DefaultBindSpec. Clients who want default validators and converters created for them just create a DefaultBindSpec as opposed to a (rather empty) BindSpec. I will also move the early type checking into DefaultBindSpec to make it optional as well.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/DataBindingContext.java
* @return the observable list containing all validation errors
	 */
	public IObservableMap getValidationStatusMap() {
		return validationStatusMap;
	}
	/**
	 * @param fromType
	 * @param toType
	 * @return whether fromType is assignable to toType
	 */
	public boolean isAssignableFromTo(Object fromType, Object toType) {
		for (int i = bindSupportFactories.size() - 1; i >= 0; i--) {
			BindSupportFactory bindSupportFactory = (BindSupportFactory) bindSupportFactories
					.get(i);
			Boolean result = bindSupportFactory.isAssignableFromTo(fromType,
					toType);
			if (result != null) {
				return result.booleanValue();
			}
		}
		if (parent != null) {
			return parent.isAssignableFromTo(fromType, toType);
		}
		
		return true;
	}
	/**
	 * Adds the given binding to this data binding context.
	 * 
	 * @param binding