Load fuzzy finder paths in web worker at startup

Previously the paths were first loaded when the fuzzy finder
view was first attached.

Now a web worker is started when the package activates that
sets the paths on the fuzzy finder view the first time it
displays if the worker has completed by the time an event occurs
that displays the view.

src/app/git.coffee

@@ -1,4 +1,3 @@
-$ = require 'jquery'
 _ = require 'underscore'
 Subscriber = require 'subscriber'
 GitRepository = require 'git-repository'
@@ -6,9 +5,9 @@ GitRepository = require 'git-repository'
 module.exports =
 class Git
 
-  @open: (path) ->
+  @open: (path, options) ->
     try
-      new Git(path)
+      new Git(path, options)
     catch e
       null
 
@@ -24,9 +23,12 @@ class Git
     working_dir_typechange: 1 << 10
     ignore: 1 << 14
 
-  constructor: (path) ->
+  constructor: (path, options={}) ->
     @repo = new GitRepository(path)
-    @subscribe $(window), 'focus', => @refreshIndex()
+    refreshIndexOnFocus = options.refreshIndexOnFocus ? true
+    if refreshIndexOnFocus
+      $ = require 'jquery'
+      @subscribe $(window), 'focus', => @refreshIndex()
 
   getRepo: ->
     unless @repo?