Release 5.1 with 5.1 AssemblyVersion (#188)

* Added changelog for 5.1

* Update build for 5.1

* Fixed changelog typo

* Updated to 5.1 version data.
Removed FileVersion so stamped by build

* Updated to latest pre-release 5.1 dependencies

* Updated latest RTM dependencies
(with fileversions)

Author: andyward