Log Message:
Update eigen3 to 3.2.9

Eigen 3.2.9

 Released on July 18, 2016

 Changes since 3.2.8:
 * Main fixes and improvements:
  + Improve numerical robustness of JacobiSVD (backported from 3.3)
  + Bug 1017: prevents underflows in makeHouseholder
  + Fix numerical accuracy issue in the extraction of complex
    eigenvalue pairs in real generalized eigenvalue problems.
  + Fix support for vector.homogeneous().asDiagonal()
  + Bug 1238: fix SparseMatrix::sum() overload for un-compressed mode
  + Bug 1213: workaround gcc linking issue with anonymous enums.
  + Bug 1236: fix possible integer overflow in sparse-sparse product
  + Improve detection of identical matrices when applying a
    permutation (e.g., mat = perm * mat)
  + Fix usage of nesting type in blas_traits. In practice, this
    fixes compilation of expressions such as A*(A*A)^T
  + CMake: fixes support of Ninja generator
  + Add a StorageIndex typedef to sparse matrices and expressions
    to ease porting code to 3.3 (see
    http://eigen.tuxfamily.org/index.php?title=3.3#Index_typedef)
  + Bug 1200: make aligned_allocator c++11 compatible (backported from 3.3)
  + Bug 1182: improve generality of abs2 (backported from 3.3)
  + Bug 537: fix compilation of Quaternion with Apples's compiler
  + Bug 1176: allow products between compatible scalar types
  + Bug 1172: make valuePtr and innerIndexPtr properly return null
    for empty sparse matrices.
  + Bug 1170: skip calls to memcpy/memmove for empty inputs.

 * Others:
  + Bug 1242: fix comma initializer with empty matrices.
  + Improves support for MKL's PARDISO solver.
  + Fix a compilation issue with Pastix solver.
  + Add some missing explicit scalar conversions
  + Fix a compilation issue with matrix exponential (unsupported
    MatrixFunctions module).
  + Bug 734: fix a storage order issue in unsupported Spline module
  + Bug 1222: fix a compilation issue in AutoDiffScalar
  + Bug 1221: shutdown some GCC6's warnings.
  + Bug 1175: fix index type conversion warnings in sparse to
    dense conversion.

Eigen 3.2.8

 Released on February 16, 2016

 Changes since 3.2.7:
 * Main fixes and improvements:
  + Make FullPivLU::solve use rank() instead of nonzeroPivots().
  + Add EIGEN_MAPBASE_PLUGIN
  + Bug 1166: fix issue in matrix-vector products when the
    destination is not a vector at compile-time.
  + Bug 1100: Improve cmake/pkg-config support.
  + Bug 1113: fix name conflict with C99's "I".
  + Add missing delete operator overloads in
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW
  + Fix (A*B).maxCoeff(i) and similar.
  + Workaround an ICE with VC2015 Update1 x64.
  + Bug 1156: fix several function declarations whose arguments
    were passed by value instead of being passed by reference
  + Bug 1164: fix std::list and std::deque specializations such
    that our aligned allocator is automatically activatived only
    when the user did not specified an allocator (or specified the
    default std::allocator).

 * Others:
  + Fix BLAS backend (aka MKL) for empty matrix products.
  + Bug 1134: fix JacobiSVD pre-allocation.
  + Bug 1111: fix infinite recursion in
    sparse-column-major.row(i).nonZeros() (it now produces a
    compilation error)
  + Bug 1106: workaround a compilation issue in Sparse module for
    msvc-icc combo
  + Bug 1153: remove the usage of __GXX_EXPERIMENTAL_CXX0X__ to
    detect C++11 support
  + Bug 1143: work-around gcc bug in COLAMD
  + Improve support for matrix products with empty factors.
  + Fix and clarify documentation of Transform wrt
    operator*(MatrixBase)
  + Add a matrix-free conjugate gradient example.
  + Fix cost computation in CwiseUnaryView (internal)
  + Remove custom unaligned loads for SSE.
  + Some warning fixes.
  + Several other documentation clarifications.