During build we transpile the server source to prevent runtime transpilation with babel/register. In order to support untranspiled plugin code, we still use babel/register with special ignore options, which used to be included in cli/index.js and now is moved to src/optimize/babelOptions.js so other code that wants to initialize a server (without the cli) can also configure babel/register.
build will create it if it's missing, copy it to the build and also create a version without dev deps
release requires it and fatals if it doesn't exist
Conflicts:
tasks/build/index.js