Add missing T() wrappers for constants.

Needed for instantiation with Jet<float,N>.

Change-Id: I8ec07a844cc911a3c7f24c25797bd21c0bee07b5
diff --git a/include/ceres/jet.h b/include/ceres/jet.h
index a104707..be0ccb0 100644
--- a/include/ceres/jet.h
+++ b/include/ceres/jet.h
@@ -345,7 +345,7 @@
 // Binary / with a scalar: x / s
 template<typename T, int N> inline
 Jet<T, N> operator/(const Jet<T, N>& f, T s) {
-  const T s_inverse = 1.0 / s;
+  const T s_inverse = T(1.0) / s;
   return Jet<T, N>(f.a * s_inverse, f.v * s_inverse);
 }
 
diff --git a/include/ceres/rotation.h b/include/ceres/rotation.h
index b6a06f7..d05d190 100644
--- a/include/ceres/rotation.h
+++ b/include/ceres/rotation.h
@@ -576,7 +576,7 @@
     const T theta = sqrt(theta2);
     const T costheta = cos(theta);
     const T sintheta = sin(theta);
-    const T theta_inverse = 1.0 / theta;
+    const T theta_inverse = T(1.0) / theta;
 
     const T w[3] = { angle_axis[0] * theta_inverse,
                      angle_axis[1] * theta_inverse,