This allows building/testing Vibe programs/components without having
to specify the .lib files on the compiler command line every time.

The old setup required that, for every component requiring a server
(e.g. a DB driver), the user had ALL components installed and running
on their development system (thus, wasn't very scalable).

This is to allow debuggers to break on an uncaught exception.

This removes the dependency to HTTP code in vibe.core.args.

Related changes:
- Refactor out UID/GID stuff to its own module, which is activated by
  importing it (done in vibe.vibe)
- Fix: Vibe will not ignore --uid/--gid if it's not running as root,
  and will print error messages accordingly
- Settings in vibe.conf and the command line use the same names
- Added test

Notably, remove the vibe.http.server import.

The Win32 driver does NOT use I/O completion ports.