Add target webodf.js.zip-target
Rename product targets and add consistent prefix "product-"
Note the products which can be built currently in README-Building.md
Add note to remove build target "zip" when CI no longer uses it
Merge pull request #582 from kossebau/CIZip

Add library product (zip with webodf.js + API dox), normalize product build targets, "zip" build target flagged for removal