[mister-teddy]

• Programs that start a Node.js child process work: npm install scripts, build tools, Electron apps. Before, every such child aborted at startup.
• Same PRoot fix as Node and Electron apps can start their helper processes localdesktop.github.io#353: under the fake root, fstat on a socket became a stat of socket:[N], which fails, and Node checks its standard streams with fstat. The PRoot source and libproot.so stay the same as Local Desktop's.