Notes:
Changes: * bug fix in array index operator for cases a=foo[0] and foo[0]=a * bug fix in methods plus attributes, foo():attr will now behave correctly * bug fix in XMLElementObject - nodes from other documents are now *imported* rather than *cloned* * added AddIfNotPresent feature to XMLElementObject: this means that elements that are references but do not exist can be added on the fly (by default the feature is disabled)