Added ~ support

Thanks to @romgrk in PR #48

lib/ex.coffee

@@ -1,6 +1,6 @@
 path = require 'path'
 CommandError = require './command-error'
-fs = require 'fs'
+fs = require 'fs-plus'
 VimOption = require './vim-option'
 
 trySave = (func) ->
@@ -108,7 +108,7 @@ class Ex
   tabp: => @tabprevious()
 
   edit: (range, filePath) ->
-    filePath = path.normalize(filePath.trim())
+    filePath = fs.normalize(filePath.trim())
     if filePath.indexOf(' ') isnt -1
       throw new CommandError('Only one file name allowed')
     buffer = atom.workspace.getActiveTextEditor().buffer
@@ -124,7 +124,7 @@ class Ex
     buffer.load()
 
   write: (range, filePath) ->
-    filePath = path.normalize(filePath.trim())
+    filePath = fs.normalize(filePath.trim())
     deferred = Promise.defer()
 
     editor = atom.workspace.getActiveTextEditor()

package.json

@@ -15,7 +15,8 @@
     "underscore-plus": "1.x",
     "event-kit": "^0.7.2",
     "space-pen": "^5.1.1",
-    "atom-space-pen-views": "^2.0.4"
+    "atom-space-pen-views": "^2.0.4",
+    "fs-plus": "^2.2.8"
   },
   "consumedServices": {
     "vim-mode": {