Initial import of eigen 3.1.1

Added a README.android and a MODULE_LICENSE_MPL2 file.
Added empty Android.mk and CleanSpec.mk to optimize Android build.
Non MPL2 license code is disabled in ./Eigen/src/Core/util/NonMPL2.h.
Trying to include such files will lead to an error.

Change-Id: I0e148b7c3e83999bcc4dfaa5809d33bfac2aac32
diff --git a/failtest/block_nonconst_ctor_on_const_xpr_0.cpp b/failtest/block_nonconst_ctor_on_const_xpr_0.cpp
new file mode 100644
index 0000000..40b8201
--- /dev/null
+++ b/failtest/block_nonconst_ctor_on_const_xpr_0.cpp
@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    Block<Matrix3d,3,3> b(m,0,0);
+}
+
+int main() {}