[Cleanup]
Fixes #212: ListViewRow can't be created with DictionaryMappedItemFactory

Created workaround that searches for parent DataGrid, finds its header and instantiates White wrapper. Plus unit test.
Merge pull request #214 from ivan-danilov/fix-212

Fix 212: ListViewRow can't be created with DictionaryMappedItemFactory
Fixes #186 yet one time: the problem with typing text is still reproducible. Only on slow Virtual Machines, only rarely, but still exist.

Presumably the problem is in the fact that SendInput adds items to Hardware Input Queue, which is being handled by Raw Input Thread. And if white calls WaitForInputIdle method on system-under-test app before simulated input is taken out of the Hardware Input Queue - it doesn't wait because application's input queue is empty - new items weren't added there yet. I don't know any way to wait exact time until raw input is processed, so I have added just plain Thread.Sleep. As Raw Input Thread works in OS with High priority - I hope it will be enough to mitigate the remains of the problem entirely.

See here for some details: http://blogs.msdn.com/b/oldnewthing/archive/2014/02/13/10499047.aspx
Minor fix: white crashes sometimes if process under test is suddenly closed.
Merge pull request #230 from ivan-danilov/some-uia-v3-fixes

Yet some uia v3 fixes
Made time waited for raw keyboard input to be processed configurable.