Merge pull request #3 from takeshik/master

Trivial Position fixes
add COPYRIGHT to all the sources
change signature of Parseq.Position's constructor to `Position(Int32 line,
Int32 column, Int32 index)`.
remove Parseq.Test
remove Examples
add Testings
update Parseq/Extensions.cs
add utility class `Foldable`
refactoring
modified signature of Foldable.Unfoldl and Foldable.Unfoldr.
support conversion to Parseq.Stream<Byte> from System.IO.Stream.
fix a bug that it is not disposed StreamExtensions.AsStream's parameter.
add wrapper class StreamDisposer<T, TObj>.
support conversion to Parseq.Stream from System.IO.StreamReader.
Add some Tests to Parseq.Test/Combinators/PrimsTest.cs

add some Tests, and fix some bugs association with it.
Remove some methods
remove Parseq.Flows.IsSuccess
remove Parseq.Flows.IsFailure
remove Parseq.Flows.IsError
add alternative methods of Parseq/Combinators/Flows.Is*
Add null check
Rename Erros.Filter method to Errors.Rescue in Parseq/Combinators/Erros.cs
Add Test of Parseq/Combinators/Errors.cs
Change the Assembly Version to 2.0.0.0
Update Parseq.nuspec