Fix building on running on Windows Debug. (#82)

* Fix building on running on Windows Debug.

In particular, we need to set the python executable properly
when running on Windows Debug.  While we are in here, we also
fix up some dependencies in the package.xml and CMakeLists.txt.
We also have to remove WERROR ON, due to some Python
warnings that are outside of our control.  Finally, we heavily
reduce the number of tests being run here so that the tests
complete in a reasonable amount of time, even on (slow) Windows
debug.

Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>

src/laser_geometry/laser_geometry.py

@@ -38,11 +38,11 @@ class LaserProjection:
     """
     A class to Project Laser Scan
 
-    This calls will project laser scans into point clouds. It caches
+    This class will project laser scans into point clouds. It caches
     unit vectors between runs (provided the angular resolution of
     your scanner is not changing) to avoid excess computation.
 
-    By default all range values less thatn the scanner min_range,
+    By default all range values less than the scanner min_range or
     greater than the scanner max_range are removed from the generated
     point cloud, as these are assumed to be invalid.