Rodriques instead of Rodriquez (he was french), and other minor erros in documentation

Change-Id: Icb56acffb373f064314ecda1e91a728cfacd07b4

docs/source/modeling.rst

@@ -378,7 +378,7 @@ having to touch the problem once it has been successfuly modeling.
    subclass of :class:`CostFunction` such that the
    :func:`CostFunction::Evaluate` function ignores the ``jacobians``
    parameter. The numeric differentiation wrapper will fill in the
-   jacobian parameter if nececssary by repeatedly calling the
+   jacobian parameter if necessary by repeatedly calling the
    :func:`CostFunction::Evaluate` with small changes to the
    appropriate parameters, and computing the slope. For performance,
    the numeric differentiation wrapper class is templated on the

docs/source/tutorial.rst

@@ -554,7 +554,7 @@ instance of this object responsible for each image observation.
 
 Each residual in a BAL problem depends on a three dimensional point
 and a nine parameter camera. The nine parameters defining the camera
-can are: Three for rotation as a Rodriquez axis-angle vector, three
+are: three for rotation as a Rodriques' axis-angle vector, three
 for translation, one for focal length and two for radial distortion.
 The details of this camera model can be found the `Bundler homepage
 <http://phototour.cs.washington.edu/bundler/>`_ and the `BAL homepage