Full symbolic RPN calculator using Sympy with a programmable calculator using exprtk c++. For SailfishOs.
Based in part on https://github.com/lainwir3d/sailfish-rpn-calculator
I've extended it with an interface to exprtk for programmable calculations. Eventually, I'll expose the sympy interfaces in a similar fashion.
It may all be merged back into @lainvir3d's project if he is so inclined.
