Report the number of line search steps in FullReport.

Accumulate the number of steps of the line search algorithm
and report it as part of Summary::FullReport.

Change-Id: I1de12784009a3e08f2a2c2aff5085d57a3c73828

include/ceres/solver.h

@@ -811,6 +811,13 @@ class CERES_EXPORT Solver {
     // Number of times inner iterations were performed.
     int num_inner_iteration_steps;
 
+    // Total number of iterations inside the line search algorithm
+    // across all invocations. We call these iterations "steps" to
+    // distinguish them from the outer iterations of the line search
+    // and trust region minimizer algorithms which call the line
+    // search algorithm as a subroutine.
+    int num_line_search_steps;
+
     // All times reported below are wall times.
 
     // When the user calls Solve, before the actual optimization

include/ceres/version.h

@@ -32,7 +32,7 @@
 #define CERES_PUBLIC_VERSION_H_
 
 #define CERES_VERSION_MAJOR 1
-#define CERES_VERSION_MINOR 11
+#define CERES_VERSION_MINOR 12
 #define CERES_VERSION_REVISION 0
 
 // Classic CPP stringifcation; the extra level of indirection allows the