Write a `pre-push` git hook.

[nexushoratio]

Yesterday I types git push rather than git stash push and pushed code that was not ready (mostly neither the app nor the library did not have their versions updated).

Put checks into place that any *.js* file being pushed has appropriate updated version lines.

• [x] Initially a -c skip.prepush flag (like the -c skip.issue flag), otherwise always fail
• [x] Check for diff line that matches ^// @version in all .js files
• [x] Verify that ^// @version and ^ const version = lines match in libraries.

[nexushoratio]

Case in point: I just noticed that lib/base.js has this:

// @version     6
  const version = 5;