g is function that returns Option
Merge pull request #17 from searler/pxmap_doc_branch

g is function that returns Option
Rough performance test of vector codec
Add listN and vectorN combinators
Rename listN to listOfN and vectorN to vectorOfN
Upgrade to scodec-bits 1.0.3
Bump version to 1.4
Update README
Fix doc comment in reunit
Fix constantLenient decoding
Simplify implementation of ReUnit by reversing order of type params - note: not binary compatible with 1.2/1.3