Upgrade barcodes, more pylint, new Ean2 code and extended Ean13 with automatic Ean2 and Ean5 additions
[Bug #1545726] Incorrect FSF address in many extension files.
Barcode extension: Code cleanup and merge in delta from last year.
Extensions. Barcode extension refactoring (see https://code.launchpad.net/~doctormo/inkscape/barcode-refactor).