NICTA/xsharpx — pull request #8 by vmarquez (2014-01-15 00:55:18+00:00)
Title: Monadic extension for Task, 

TaskExtension provides monadic extensions to Microsoft's [Task](http://msdn.microsoft.com/en-us/library/dd321424(v=vs.110).aspx) class. Note that constructing and comprehending Tasks is referentially transparent, only calling "Start" will kick off the computation in another thread on the environment's thread pool.

EitherTTask is analogous to an EitherT if .NET allowed HKT, in other words a way to comprehend over both the Either and the Task in an easy to use way.

Sequence is self explanatory, though we may want to move it to List?