Corrected elapsed time console print in line 73

Corrected return value for watch.getTimeSeconds() from int to double. Also corrected message that said time was in milliseconds, when watch.getTimeSeconds() returns elapsed time in seconds.
Merge pull request #739 from georgebrindeiro/patch-1

Corrected elapsed time console print in line 73
model outlier removal contribution
Code upate
Signed-off-by: Victor Lamoine <victor.lamoine@gmail.com>
Update tutorial
Remove model_from_normals_ class member
Use pcl::isFinite instead of pcl_isfinite
Change cloud_normals_ into a const ptr