add crystals to the main branch of Sage

[mwhansen]

CC: @sagetrac-sage-combinat

Component: combinatorics

Issue created by migration from https://trac.sagemath.org/ticket/2742

[mwhansen]

comment:2

Attachment: trac_2472-crystals.hg.gz

People who had patches in this bundle:

Jason Bandlow
Dan Bump
Mike Hansen
Anne Schilling
Nicolas Thiery
Justin Walker

Positive review from me.

[sagetrac-mabshoff]

comment:3

Merged in Sage 3.0.alpha0