Fix for Issue #930
sortedIndex documentation

Adding note about using strings as iterators and an example.
Merge pull request #1001 from burin/sorted-index-docs

sortedIndex documentation
Correct stooges example with the correct stooges.
Fixes #982. Fixing  to have a lower defined behavior bound of 1.
Merge pull request #981 from rafalchmiel/patch-1

Fix for Issue #930