crypto: basic crypto functions
crypto - second draft, including suggested changes
crypto: basic crypto functions
crypto - thrid draft
Docstring and test cleanup for the crypto module
Merge pull request #1 from asmeurer/joyner_crypto

Your patch from https://github.com/sympy/sympy/pull/1854/files#r3310621
Merge remote-tracking branch 'github/crypto' into crypto
Docstring and test and html cleanup for the crypto module
Implemented Morse encoding and decoding
Restricting enciphering only to alphabets and digits
Merge pull request #2 from ankit-maverick/crypto

Implemented Morse code and Restricted enciphering only to alphabets and digits
Minor refactoring
Merge pull request #3 from ankit-maverick/crypto

Minor refactoring
Improve subs for Derivative.

Perform substitutions if derivative variables are in a different, but
equivalent order and perform substitutions for subderivatives.
Add additional tests for Derivative subs method.
polys: implement modular GCD algorithm for univariate integer polynomials
polys: add tests for modgcd_univariate()
polys: implement modular GCD algorithm for bivariate integer polynomials
polys: add tests for modgcd_bivariate()
polys: implement modular GCD algorithm for multivariate integer polynomials