Adds `indexOf` support to the List API
Allows to `select` list elements before the list is rendered for the
first time.  This can happen when you try to select an item in a
list, right after it has been created.
Adds `indicesOf` to obtain all indices.
Rename to getFirstListIndexOf/getListIndicesOf.
Merge pull request #38 from angerman/master

Minor List improvements.