[DIGESTER-72] Allow SetNextRule to fire on begin

I added an abstraction layer in order to support the same feature not only for SetNext, also for SetRoot and SetTop.
xmlrules and annotations are supported as well

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1140212 13f79535-47bb-0310-9956-ffa450edef68
26 files changed