add but-2-ene and use example-file where appropriate
update probably unused project.clj
initial reaction lisp functions
add atoms and bonds functions, use atoms where appropriate
add get-atom-container-exact-mass and friends
export atoms and bonds functions
add and export get-atom-atom-mapping function
add CDKConstants and Isotopes jimport forms
use absolute SmilesGenerator instead of isomeric SmilesGenerator
add reaction.lisp to the ASDF system definition
add but-2-ene and an example get-atom-atom-mapping call