Wouter engine improvements
I've made some small improvements to the OCSR code. Could you review them?
Although the changes are small, I understand if you want to wait until after the first release.
Note: You may want to double-check that my last commit (the merge) has preserved all your latest changes.
Functional changes:
- Made the CSV writer optional.
- Made the main load/run methods more consistent.
- Removed some unnecessary method parameters in World/CrowdSimulator.
- Set the example's timestep to 0.1 seconds.
C++ improvements:
- Improved use of const/references.
- Fixed "type conversion" warnings.
- Improved use of relative file paths; this will be useful for a DLL later on.