PR: Expanded type coersion

Accepted a PR from @jameshulse-justgiving to improve the mapper's ability to convert types, to add support for binding to TimeSpans

Version bump

Just fixing the version in the nupkg file

Added support for nullable values

v1.3.0

Added support for nullable types

Interface love

Added the ability to bind to pure interface definitions by custom-emiting a concrete implementation

Initial Nuget release V4

v0.1.1

fix to readme.md