X-point geometries
A study of X-point grids
- removed trailing whitespaces in inc and geometries files
- updated memory class to std11, renamed Handle class to ClonePtr
- merged optimized sparseblockmat kernels and added avx to default config files
- fixed memory bug caused by Tensor class design
- new file conformalX_elliptic_b.cu
- corrected faulty namespace in diag programs
- specific updates in inc/dg/geometries due to new X-point paper