Haxelib "boot"

I propose the following for replacing haxelib.exe:

In OCaml:
- rewrite the method responsible for resolving haxelib repository (which is quite easy)
- locate the current haxelib package installed using this method
- if not present, install it from statically linked data
- run it using haxe eval

This way:
- no neko dependency required (only for running run.n if necessary)
- haxelib can be distributed/updated as a library

Show stopper:
- eval ssl support ?