add BeanFactory
bump to version 3.1 for factory beans
add test for factory failure
delete object if fails to build
use cget instead of upvar for checking properties reliably
follow Spring framework's technique for BeanFactory. Property set to a BeanFactory will automatically call getObject. Filling in a property with a beanFactory can be done by proceeding the bean name with an ampersand
Merge branch 'master' of pxsvn:/usr/local/git/di-tcl