Mol2 parser

Used TokenColumns. Read first line to determine which column is missing. Read each value at a time and add start and end indices to corresponding tokens. There is an error about async wait of handleAtoms and handlebonds Funcitons because they don't have async functions inside them and maybe they don't return Promises anymore. Used to use readLinesAsync which is a async function. But now use skipWhitespace and eatValue, which don't have async versions.