Updated ImageViewerSamples solution

* Moved the viewer samples solution to the Samples directory, to make it easier
  to find.
* Fixed various paths and outdated items in the build scripts and solutions.
* Fixed compile error in the ROI analysis example.

#17

--HG--
rename : ImageViewer/ImageViewerSamples.sln => Samples/ImageViewerSamples.sln
rename : ImageViewer/ImageViewerSamples_dist.proj => Samples/ImageViewerSamples_dist.proj
extra : rebase_source : 7c6f980c8c1b54fe3dd8dc6da3737d54d51284e2
Clean up of build warnings in viewer samples solution

* Removed usages of IconScheme and associated IconSet attribute.
* Replaced usages of ClearCanvasStyle with Application Themes.
* Updated discussion forum link to point to GitHub instead.
* Reformatted code.

#9, #17

--HG--
extra : rebase_source : f76b0813d2df9f0622e5ecd5905a330243ce3240
Updated ImageViewerSamples solution

* Updated samples solution to support a native x64 build.
* Removed the ITK sample plugin due to a lack of an x64 ManagedITK build.

#17