Add support for the current Babel 7

[prantlf]

Aims to fix #32.

This change requires editing the paths property of the RequireJS configuration and adding babel modules as a dependency to the client project. As such it is a breaking change and should be released as a new major version. Although the function resolveModuleSource is not necessary to configure any more, it is supported for compatibility.

• Depend on babel-plugin-module-resolver-standalone as a replacement for the removed support for resolveModuleSource in Babel.
• Remove the copy of babel-standalone. The newest version supported by this plugin should be loaded by the client.
• Declare @babel/standalone and babel-plugin-module-resolver-standalone as dependencies to give a hint, that they have to be added by the client.
• Add another demo project demonstrating integration of @babel/polyfill and babel-external-helpers to be able to use the async/await syntax.
• Include package lock to follow NPM best practices.
• Do not mention bower, which has been deprecated in favour of NPM.

[mikach]

Thanks a lot! Unfortunately, I don't have a lot of time to support this and I consider using webpack is better option nowadays then using requirejs with this library, but anyway thanks for your contribution!