Fix getChannel in the Image class

The getChennel was not working correctly due to the Eigen Map class.
When assigning values to it, ie:

  image->getChannel(0) = ...

The outer stride was incorrect, ie, it was just the number of rows (for
column major storage), when it should be the number of rows times the
inner stride (the number of channels in this case). I expected using the
InnerStride class would have calculated the outerstride on the fly. So
instead, the Eigen::Stride class is used here, and we calculated the
outer and inner stride.

This fix also contains unit tests to demonstrate the error.
Add different data type copy to Image

Add a copy constructor that can take a pointer to data of a different
type. This causes the constructor to convert the data type as well as
copy.
Add getAsVector to Image

Add new member function to the Image that returns the entire image as a
1D vector. This makes it easy to do simple operations to all the data,
like scaling, addition, etc.
Add setChannel and setAsVector to Image

Add setChannel and setAsVector to the Image data structure. This
provides customary set access here. Also, make it more clear that the
getChannel and getAsVector return mutable access to the Image data, by
providing const and non-const versions of these functions.
Fix comment in Device Scaffolds

All the device scaffolds had a comment referring to a SingleInstance.
This class was renamed to SharedInstance, this change updates the
comments.
Set Eigen Maps in Image class to Unaligned

When running in Debug mode, the data pointers in the image class are not
aligned (16 byte aligned?). They are in Release mode. So turning off
alignment for the Eigen::Maps, until we ensure these pointers are
aligned correctly.
Fix some whitespace formatting and an unused file

Couple of hanging whitespace issues, long lines, and removed a file
TokenStreamTest that isn't being used.
Prevent Runtime from calling stop twice when shutting down
Prevent OsgManager from dumping out its scenegraph automatically when not in debug
Make runtime responsible to load a scene

This enables reloading of a scene
Merge branch 'fix/cpplint-formatting' into 'master'

Formatting fixes

+1: Ryan Beasley, Julien Lenoir, haizhouW

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1185783
Merge branch 'feature/image-additions' into 'master'

Fix Image getChannel and a couple of features

+1: Ryan Beasley, Harald Scheirich, haizhouW

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1171803
Merge branch 'fix/device-comment' into 'master'

Comment fix in Devices

+1: Ryan Beasley, Julien Lenoir, haizhouW

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1180443
Slight rewrite, documentation change
Merge branch 'fix/yaml-scene-loading' into 'master'

Add loadScene() to Runtime

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1187263
Merge branch 'fix/runtime-stop-error' into 'master'

Prevent runtime from calling stop twice when shutting down

+1: haizhouW, Paul Novotny, Julien Lenoir

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/1186893