New API: Multibinder.permitDuplicates() and MapBinder.permitDuplicates()

When a map binder is configured to permit duplicate keys, the value chosen is arbitrary! This may be frustrating; but otherwise it would be necessary to actually call Provider.get() on the duplicated values to compare 'em; I think the cure would be worse than the disease

git-svn-id: d779f126-a31b-0410-b53b-1d3aecad763e
4 files changed