Improve the release process with a documented workflow supported by scripts

[happybeing]

Make use of github release features, but aiming roughly for something like:

• build scripts creates output for each platform in it's own ./dist subdirectory
• specify testing required before release (handle multiple platforms)
• tag release with vX.Y.X or vP.Q.R-rc1 etc
• automate the process using a build-release script that can run on each platform, including copying libs
• ensure scripts are cross platform (e.g. using node rather than bash)
• maybe ability to build package for 'mock' network with a -dev included in the zipped archive name
• make sure large files (e.g. the zips and built exes) don't make it into git (using .gitignore)

The above are just ideas. I suggest beginning with a look at the github release feature and then put forward a proposal.

Note: I think the current build script fails on Windows because of differences between shell commands from Linux. For example some file system operations such as mkdir -p or copying a folder (I might be misremembering though). Here's a nodejs library that should help fix those issues: https://github.com/shelljs/shx