Merge pull request #111 from tgriesser/second-next

Adds second / next functions
Add map-indexed
Merge pull request #114 from tgriesser/map-indexed

Add map-indexed
fix versions, bump cljs dep
Expose comparison functions, fixes #112
Transducers, mori.reducers

Adds mori.reducers namespace, moving r prefixed fns
to this namespace. Adds tranduce and related transducer
functions.
Basic protocol support for JS objects via mori.extend
Update .extend api
Add IIndexed protocol