Set telepath.devMode to true when not on an official release

This will enable assertions inside of telepath to help us diagnose
atom/telepath#7. Otherwise, the issue *should* be covered over for end
users.

src/atom.coffee

@@ -9,7 +9,8 @@ dialog = remote.require 'dialog'
 app = remote.require 'app'
 
 _ = require 'underscore-plus'
-{Document} = require 'telepath'
+telepath = require 'telepath'
+{Document} = telepath
 fs = require 'fs-plus'
 {Subscriber} = require 'emissary'
 
@@ -53,6 +54,8 @@ class Atom
     {devMode, resourcePath} = atom.getLoadSettings()
     configDirPath = @getConfigDirPath()
 
+    telepath.devMode = not @isReleasedVersion()
+
     Config = require './config'
     Keymap = require './keymap'
     PackageManager = require './package-manager'