Split the main package in two: a proxy package with core objects and a small main package

[dlespiau]

At the moment we have the main package with the core objects (proxy, vm, ioSession, ..) and the main function. The problem with those objects being part of the main package is that golint doesn't pickup some "issues" (eg. undocumented exported symbols).

Plan is to split the main package in two so golint can do its work and we have a clean separation between the main function and the core objects.