(cleanup) Re-exported most commonly used names directly from iron.
(cleanup) Fixed example to use new imports.
Merge pull request #26 from reem/cleanup/names

(cleanup) Re-exported most commonly used names directly from iron.
(doc) Updated README to use type synonyms.
Merge pull request #27 from zzmp/doc/type-syn-README

(doc) Updated README to use type synonyms.
(doc) Documented iron/mod.
(doc) Updated iron/mod for readability.