Improved thread naming

If Work has only a dedicated thread there is no need of number
The Work.Context of ArrayPool is called "Recycler"
WeakNeedle<T> now implements IEquatable<...>
Style fix
StructNeedle<T> now implements IEquatable<T>
Put On Pair

Changed properties Pairs to methods GetPairs
Changed properties Values to methods GetValues and added overload that
takes a Converter
Style Fix
FIxed a bug in Work: the string formats were wrong