Fixes to Ico's branch to make it work with the older nw.js versions we're using on the supported platforms

This MR serves to document regressions with Ico's branch and to collect all the fixes required for older nw.js versions on our supported platforms, to be merged back into the ico-nwjs-04x branch which in turn is to be merged back into master once we've fixed all the regressions. I've started it off with the fix to make window creation work again on older nw.js versions (especially 0.24.4), as suggested by Ico, but further commits are to be added here as we identify regressions and find fixes for them.