extension methods and cleanups

- ADD: EnumerateControls() extension methods
- CHG: code cleanups
GUI, projects, collections, extension / helper methods, compatiblity, improvements, fixes and cleanups

- ADD: started to implement "Drag 'N Batch" project
- ADD: draggable borderless base classes for WPF and WinForms
- ADD: BooleanToVisibility WPF converter
- ADD: base WPF value converter class that can handle a separated string
list of parameters
- ADD: IInitializable interfaces
- DEL: removed overwritten collection helper methods in .NET 3.5 libs
and later
- ADD: IGeneralList interface
- ADD: System.Action<T1, T2, T3> for pre .NET 3.5 systems
- FIX: minor documentation fixes
- CHG: code cleanups and improvements
added AddRangeOf<T>() method to IGeneralList interface