Added Value with consturctor and ValueBase empty

Asked by Sasha
my changes
Value, ValueBase and IPack implementation

added new class "Pack" inside Dictionary2d.cs
ValueBase values initialized, Pack class as separate file, XML comments added

#6
i have no clue for the moment what Enumerator should return
currently returned values are only what i found matching returning
format
possible its smth need to do about keys matching but currently i dont
follow
Merge pull request #11 from qlynn/medvedchuk

updated Values and ValueBase, implemented Dictionary2d.GetEnumerator, added new Pack class