* add a test
* change stereo bond canonicalization
* update canonicalization watch test with fixed cases
* make canonicalization test stricter (compare CIP codes)
* add reverse symmetry condition
* rewrite double bond canonicalization code
* update tests
* fix multiline comment
* update java tests
* update python test
* nix switchBondDir (unused)
* fix and rename flipBondDir
* refactor comment
* fix shadowed var name, casting
* fix neighbor sorting
* make seen_bonds a vector
* abstract setDirectionFromNeighboringBond
* handle both sides of the bond have directions
* move getNeighboringStereoBond
* check seen_bonds after popping connectedBondsQ
* use references for arguments
* add release note
* add example required by Dan
* add example requested by Dan