Substantial update to glypy.synthesis to support both N-glycans and Mucin type O-glycans.
Added SNFG symbolic nomenclature and set as the default symbolic nomenclature.
Rewrote most structure drawing infrastructure to be less magical and more linear
Added new canonicalize module to glypy.algorithms for reordering Glycan objects according to sorting rules to control traversal order. Uses the published GlycoCT canonicalization method. Added new method Glycan.canonicalize.
Fixed several defect sin glypy.algorithms.subtree_search