container stride algorithm and tests
Fix incorrect header includes for and multiset
Merge pull request #73 from pfultz2/header-fix

Fix incorrect header includes for multiset
experimenting with Python-ic slice operations on ranges: rng[{from,to}] is synonymous with view::slice(rng, from, to)
more Python-ic goodness: rng[{4,end}] is synonymous with drop(rng, 4)
slice offsets can be relative to the end, with rng[{end-4,end-2}]