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

This release includes improvements in IUPAC and Enum handling

Fixed a major issue in Glycan.crossring_subtrees failing to generate glycosidic cleavages because .link_index was unpopulated after copying without indexing.

Many, many minor fixes and changes owing to revisions to code coverage improvements

This is a preview release, coinciding with release on PyPI