Mfem

* Overloaded functions whose definitionsare distributed among several .hpp are
handled by common_functions.i. Such functions include Add, Mult, Transpose,
RAP, and InnerProduct.
* Due to above change, add_sparse, add_dense has been removed.
* Element access to DenseTensor object is added.
* GetDataArray of DenseTensor and DenseMatrix is changed to return a mere
memory view of objects' internal data, instead of copy of data

* common/depelicated.i is added. This interface file contains
two macros for specfing method and overloaded method as deprecated.

* Rebuild all cxx to work with MFEM 3.3.2
* mesh::GetBdrElementAdjacentElement is wrapped to return two integers

2017 10.10 chypre.py
* CHypreMat::__add__ and CHypreMat::__sub__ was calling CHypreMat without
specifing col_parts.

* bilininteg.i is adjusted so that NonlinearIntegrator is properly recognized
as a base class of BilinearIntegrator class. This allows to use SetIntOrder
and some others in BilinearIntegrator

* Mesh.GetElementCenterArray is added, which returns numpy array

* cuda build is tested
* In solver.hpp, many routines takes Operator &, but FormLinearSystem
takes OperatorHandle. A new typemap (operator_ptr_typemap) is added to
call OperatorHandle -> Ptr() inside the wrapper so that one can pass
OperatorHandle to the routines such as SetOperator, PCG and etc.