chemIdResolv.php: new script which will use the PubChem cactus service to try to find chemical identifiers..
schemeViewer.js: add moleculeViewer function and actually use width/height parameters.
* main.css: additions to accommodate new product entry dialog
* editXP-exec.php: save products grid where present, for chemistry. Also deal better with uninitalised values to suppress Notices.
* loupe-15px.png: Public domain, from Wikimedia Commons https://commons.wikimedia.org/wiki/File:Loupe.svg
* editXP.php: Add products grid to end of chemistry experiments. Button and jquery dialog to add a compound. Button in that dialog to look up names of structural compounds on pubchem. Also reflect some file renames, add function preSubmit(), and add hidden fields for rxn/grid/prodGrid (these were previously in external js).
* viewXP.php: filename change for unit-converters.js.
* chem-formatters.js: add delButtonFormatter, copyButtonFormatter. Remove buttonFormatter. Add percentFormatter, and mass/mol/yield total formatters.
*  chemistry-functions.js: renamed unit-converters.js
* edittableScheme.js: remove hidden fields and preSubmit() to editXP.php.
* stoic-table-edit.js: change formatter for del field.