GitLab

Changed the copy constructor for tensors, as there was a conflict for a symmetry modifying constructor. To get rid of the default copy constructor it was necessary to define both templated and parent (untemplated) class constructors rather than just the latter.

This will break codes that used Tensor B(A, false/true), which now needs to be Tensor B(false/true, A)

Changes to interface, added internal namespace, new convention is for internal classes to be lower case and for external classes to be capitalized

Started writing interface for semirings, which tries to expose type-templated semirings, but type-free tensors (on typed rings)
by autocasting templated semirings into (char *)-based semirings, pretty wild, but the point is to have an elegant typed interface
without instatiating everything for every type defined by the user.

Made MPI_Comm_split happen on-demand rather than at start-up for all the torus topologies.

Added MPI_Finalized(..) check to make sure that CTF exits gracefully (without freeing the main comm)
if a user calls MPI_Finalize() before destroying a CTF_World

 - diagonal contractions with not all edge lengths equal
 - read_all had a short circuit
 - CTF_VERSION 100 now defined

Also fixed a bug with A*A, which I introduced ~5 commits ago when fixing multi-tensor symmetric contractions.

Implemented a scheme that tries to find contraction mappings that keep a tensor frozen to its original layout