Merging with SymEngine

[teaalltr]

Is it viable? To what extent?

Pros:

• common codebase, more collaboration
• better mantained
• simpler and more optimized code

Cons:

• re-engeneering overhead
• code refactor, so...
• ...(few | some | a lot of) time

I expecially mean the WIP @poke1024 C++14 implementation If not viable at all, another option would of course be using it as an external library

[isuruf]

@Piruzzolo, let us (SymEngine developers) know what we can do.