fix formatting for (non-generated) internal source files

- Change formatting standard to Cpp11. Main difference is not having
  the space between two closing >> for nested templates. We don't
  choose c++14, because older versions of clang-format (version 9
  and earlier) don't know this value yet, and it doesn't make a
  difference in the formatting.
- Apply clang-format to all (non generated) internal source files.
- Manually fix some code sections (clang-format on/off) and c-strings
- Exclude some embedded external files with very different formatting
  (gtest/gmock)
- Add script to format all source files

Change-Id: Ic6cea41575ad6e37c9e136dbce176b0d505dc44d

internal/ceres/parameter_block_ordering_test.cc

@@ -61,7 +61,7 @@ class DummyCostFunction : public SizedCostFunction<M, Ns...> {
 };
 
 class SchurOrderingTest : public ::testing::Test {
- protected :
+ protected:
   void SetUp() final {
     // The explicit calls to AddParameterBlock are necessary because
     // the below tests depend on the specific numbering of the
@@ -75,8 +75,8 @@ class SchurOrderingTest : public ::testing::Test {
     problem_.AddResidualBlock(new DummyCostFunction<6, 5, 4>, NULL, z_, y_);
     problem_.AddResidualBlock(new DummyCostFunction<3, 3, 5>, NULL, x_, z_);
     problem_.AddResidualBlock(new DummyCostFunction<7, 5, 3>, NULL, z_, x_);
-    problem_.AddResidualBlock(new DummyCostFunction<1, 5, 3, 6>, NULL,
-                              z_, x_, w_);
+    problem_.AddResidualBlock(
+        new DummyCostFunction<1, 5, 3, 6>, NULL, z_, x_, w_);
   }
 
   ProblemImpl problem_;