docs: document common npm dependencies

Closes #5299
Merge pull request #5390 from robertkowalski/docs-git-dep

docs: document common npm dependencies
char-spinner: update to not bork windows
v1.4.14
bump ansi and associated deps
columnify@1.1.0
editor@0.1.0
github-url-from-username-repo and read-package-json updates

Prefer https:// git urls instead of git://
Update glob and things depending on glob
graceful-fs@3
ini@1.2.1
more minor dep bumps
Update osenv@0.1.0 which removes ~/tmp as possible tmp-folder

Closes #3470
Use `npm.config.get('prefix')` instead of `globalPrefix` getter

`defaults` getter in  `npmconf`'s `config-defs.js` covers all the cases
we need for global prefix resolution, while the getter didn't even load
the config file before determining the global prefix.

`globalPrefix` getter remains unused and should be removed from
`npmconf`.

Fixes #5343.