3.0.0-beta1

Backwards incompatible*: Refactor and split of the Gen and Arbitrary APIs into FsCheck.FSharp and FsCheck.Fluent. This is a first step in splitting the entire API into a functional (for F# consumers) and fluent (for C# and VB.NET consumers) interface. This should be clearer for both kinds of consumers.
By and large, if you are an F# user, now open FsCheck.FSharp in addition to open FsCheck. If you are a C# or VB.NET user, add using FsCheck.Fluent.
Backwards incompatible*: redesigned API for per-type Arbitrary instance discovery and lookup. There is no longer a single global, mutable map of type to Arbitrary instances, instead there are any number of immutable IArbMaps that can be configured at your leisure, and set via Config.WithArbitrary on the test.
Detailed changes to FsCheck.FSharp.Gen: Added RequireQualifiedAccess. Added apply and bind. Renamed collect and sequence to collect/sequenceToList/Array/Seq for clarity. Removed unzip and unzip3 - their implementation is problematic, and it's hard to see a use case for them. Removed subListOfToIlist, subListOfArr - these returned IList<'T> types. Untupled rows,cols arguments in array2DOfDim.
Detailed changes to FsCheck.Fluent.Gen: Split into non-extension methods on Gen and extension methods on Gen<T> type in GenExtensions. Removed Gen.Apply - not useful without partial application. Two, Three, Four and Zip now output ValueTuples, which is idiomatic in modern C#, and are only visible as extension methods on Gen<T>. Removed the overloads of Zip with arity 3. Changed the return type of methods that returned IList<T> previously to List<T>. Split the Sample method with optional arguments in three overloads, this is better for backwards compatibilty going forward.
Detailed changes to FsCheck.FSharp.Arb: Removed fromGenShrinkFunc. Removed register, registerByType, from, generate and shrink - these are replaced by functions on ArbMap, resp. mergeWith, mergeWithType, arbitrary and generate. Made Arb.Default internal. Default types should now be looked up using ArbMap, e.g. ArbMap.defaults |> ArbMap.arbitrary<list<int>>.
Detailed changes to FsCheck.Fluent.Arb: Removed extension method ToArbitrary that took an F# function as argument for the shrinker. Renamad Arb.From methods to Arbitrary.From - C# does not tolerate ambiguity between using two types of the same name in the same namespace. Removed Register, RegisterByType, From, Generate and Shrink - these are replaced by methods on ArbMap, resp. Merge<'T>, Merge, ArbFor and GeneratorFor. Made Arb.Default internal. Default Arbitrary types should now be looked up using ArbMap, e.g. ArbMap.Default.ArbFor<int[]>().
First pass at improving XML docs for Gen API.
Fixed bug in try..with computation expression builder.
Added support for let!...and!... syntax in computation expression builder.