Store represented directory paths directly on AtomWindow in main process

[nathansobo]

Fixes #13761

Previously, when adding a window, we were unable to read its current project paths out of the hash of the URL during window initialization because the window still considered itself to be loading. Rather than fixing this issue, we decided to completely eliminate the sharing of state between processes in the window.location and instead switch to cached synchronous RPC for the loadSettings and a dedicated RPC-based mechanism for the project paths.

🍐 'd with @maxbrunsfeld

[ungb]

taking a 👀

[ungb]

atom --version
Atom    : 1.15.0-dev-c6cae5b
Electron: 1.3.13
Chrome  : 52.0.2743.82
Node    : 6.5.0

I am still able to repro the issue in #13729.

[nathansobo]

@ungb strange. I checked again and this is working. It seems like the steps pictured in your animation are somewhat different than the original reproduction steps for the issue. I wonder if there's another issue involved. Here's what works for me:

• Open a directory in Atom atom .
• Atom opens a window for that directory. Close that window, then quit Atom.
• cat ~/.atom/storage/application.json shows an empty array. This is the evil state from before.
• Open a directory in Atom again atom .
• Quit without closing any windows first.
• cat ~/.atom/storage/application.json shows an array with a window for the opened path. This is the desired state that wasn't showing up previously when quitting Atom before blurring the window.
• Open Atom with no path atom. This restores the previous window state as expected.

[nathansobo]

Sorry, I had associated this PR with the wrong issue out of confusion. I should have referenced fixing #13761. I've updated the PR body accordingly.