Separate sandbox examples into stand-alone projects

See merge request iMSTK/iMSTK!251

1 or 2 line descriptions are added for each example.

Remove shader compilation code from audio example
remove PBDFluid benchmarking example

COMP: Update the Eigen remote repo link

See merge request iMSTK/iMSTK!249

COMP: rename output debug lib for gmock/gtest

See merge request iMSTK/iMSTK!248

COMP: Update Google Test to fix compilation on msvc 15 2017

See merge request iMSTK/iMSTK!247

Addresses following issue:
https://github.com/google/googletest/issues/1373

Add multiple sources for Libusb download

See merge request iMSTK/iMSTK!245

Sometimes the sourceforge server appears to be down, stopping us from
downloading libusb1.0. We now add a second url to fetch the libusb
package from data.kitware.com

To include following feature:
cmake/cmake@2eec433f

Fix ubuntu

See merge request iMSTK/iMSTK!246

https://github.com/assimp/assimp/issues/746
https://stackoverflow.com/questions/38296756/what-is-the-idiomatic-way-in-cmake-to-add-the-fpic-compiler-option

Minor refactoring of rendering and simulation manager

See merge request !244

Also enforces formatting

Also, move constructor of VTKViewer to .cpp

Use already defined enums as arguments

launchSimulation and startSimulation have similar meaninn to be included in public API.
Moved the launch simulation to be a private member.

ENH: shadows, bloom, shader options

See merge request !235