Support XDG basedir specification

[eheintzmann]

Please support FreeDesktop.org XDG basedir specification for node-gyp

http://ploum.net/post/207-modify-your-application-to-use-xdg-folders
https://live.gnome.org/GnomeGoals/XDGConfigFolders
http://standards.freedesktop.org/basedir-spec/latest/

[TooTallNate]

Seems reasonable. Someone should write a node-xdg module to kick things off...

[JayBeavers]

Closing due to age and no takers.

[Siilwyn]

@refack did you make progress on this?

I've done this for several modules using env-paths if this change can be made as a major version bump it will be straightforward to do and I'm willing to take this issue and #1124.

The relevant code is placed this right?

node-gyp/bin/node-gyp.js

Lines 19 to 23 in b2e5cf0

	var homeDir = osenv.home()
	if (prog.devDir) {
	prog.devDir = prog.devDir.replace(/^~/, homeDir)
	} else if (homeDir) {
	prog.devDir = path.resolve(homeDir, '.node-gyp')

[Siilwyn]

@rvagg thoughts? ☝️