Don't put a / on resolved gitosis-style git urls

Fixes #3224
cache: Handle cases where git url contains host more than once

Slight fixup for #3224
v1.2.27
Separate tar and cache lockfile usage

Folders were getting double-locked, resulting in an unnecessary 1000ms
hang for everything added to cache.  Since we tar things multiple times
(stupidly) this led to about a 5-10s increase in latency for lots of
operations.

Fix that by adding 'tar://' to the start of all the locks created in
lib/utils/tar.js
lockfile@0.3.3
npmconf: Upgrade for new SSL keys

In 6 months or so, or probably whenever 0.12 releases, we can
switch over to use the same SSL cert and key for the registry
as the npmjs.org website, and people can stop complaining about
the registry not rendering in their web browser.