EmitHelper enhancements.

- Refactored to extract StoreDefaultValueForOutParameter reusable method.
Fixed naming & minor enhancements.

- ICKObservableReadOnlyCollection was CKIObservableReadOnlyCollection...
- New LdArgBox on ILGeneratorExtension.
- Added PopLast & PeekLast methods on FIFOBuffer: it can now be used as a LIFO stack.
Added comments, unit tests and minor modifications.

- Unifies "TargetSavor" to be "net40" and "net45" to match the
NuGet targetFramework names.
- Added a virtual on void CKObservableSortedArrayList.OnCollectionChanged.
Merge branch 'develop'