Comment cleanup from Jim Roseborough

Change-Id: Id47101fe32e1449e660ec536934ee91fdaf452c7

examples/curve_fitting.c

@@ -147,7 +147,8 @@ int main(int argc, char** argv) {
   ceres_init(argc, argv);
 
   /* Note: Typically it is better to compact m and c into one block,
-   * but in this case use separate blocks for illustration. */
+   * but in this case use separate blocks to illustrate the use of
+   * multiple parameter blocks. */
   double m = 0.0;
   double c = 0.0;
   double *parameter_pointers[] = { &m, &c };

internal/ceres/graph_algorithms.h

@@ -43,7 +43,8 @@
 namespace ceres {
 namespace internal {
 
-// Compare two vertices of a graph by their degrees.
+// Compare two vertices of a graph by their degrees, if the degrees
+// are equal then order them by their ids.
 template <typename Vertex>
 class VertexTotalOrdering {
  public: