buildAll.sh linux errors

[duncanawoods]

There are two issues:

• the original directory is not restored after it is invoked - I have used pushd/popd
• buildall.sh fails on linux - NETSDK1095: Optimizing assemblies not supported for osx/win #464 the win/osx builds fail on linux - I have disabled them if it's linux - I don't know if they work on osx

[duncanawoods]

I see that this doesn't build the electron host typescript. I also suggest adding:

pushd $dir//ElectronNET.Host
    npm run-script start
popd

[GregorBiswanger]

Thank you for your contribution! Write me your postal address on Gitter and you will get Electron.NET sticker :)