Automating NodeJS packaging as a module.

Better preparation of the node_modules gtm directory.
Incorporating it into the dist.Nodejs CMake target, to match
how the packaging is done for Python and its egg file.
Improving Node.js packaging. Dealing with paths.

Refining the organization of the node.js module package.

Creating the right structure for the module to be loaded.
Fixing final gtm.node library name.
Increased gtm node module version.

Now that packaging and module configuration has been fixed.