Improved Windows path completion.

Removed `\` and `:` from the delimiter list for Windows, and
stopped deleting `\` chars from paths on Windows.

IPython/core/completer.py

@@ -216,7 +216,11 b' def completions_sorting_key(word):'
 class Bunch(object): pass
 
 
-DELIMS = ' \t\n`!@#$^&*()=+[{]}\\|;:\'",<>?'
+if sys.platform == 'win32':
+    DELIMS = ' \t\n`!@#$^&*()=+[{]}|;\'",<>?'
+else:
+    DELIMS = ' \t\n`!@#$^&*()=+[{]}\\|;:\'",<>?'
+
 GREEDY_DELIMS = ' =\r\n'
 
 
@@ -729,7 +733,10 b' class IPCompleter(Completer):'
             return [text_prefix + cast_unicode_py2(protect_filename(f)) for f in self.glob("*")]
 
         # Compute the matches from the filesystem
-        m0 = self.clean_glob(text.replace('\\',''))
+        if sys.platform == 'win32':
+            m0 = self.clean_glob(text)
+        else:
+            m0 = self.clean_glob(text.replace('\\', ''))
 
         if has_protectables:
             # If we had protectables, we need to revert our changes to the