math/savage: New Port: Primitive computer algebra system

Savage is a new computer algebra system written from scratch in pure
Rust. Its goals are correctness, simplicity, and usability, in that
order.

Features:

 - Arbitrary-precision integer, rational, and complex arithmetic
 - Input, simplification, and evaluation of symbolic expressions
 - First-class support for vectors and matrices, with coefficients being
   arbitrary expressions
 - REPL with syntax and bracket highlighting, persistent history, and
   automatic multi-line input
 - Macro-based system for defining functions with metadata and automatic
   type checking
 - Usable as a library from any Rust program

WWW: https://github.com/p-e-w/savage