Merge pull request #3916 from suda/master

Setting ATOM_HOME

src/atom.coffee

@@ -202,6 +202,9 @@ class Atom extends Model
     # Make react.js faster
     process.env.NODE_ENV ?= 'production' unless devMode
 
+    # Set Atom's home so packages don't have to guess it
+    process.env.ATOM_HOME = @getConfigDirPath()
+
     @config = new Config({configDirPath, resourcePath})
     @keymaps = new KeymapManager({configDirPath, resourcePath})
     @keymap = @keymaps # Deprecated