Remove Inotify._remove_watch_bookkeeping

- The call on inotify_event.is_ignored was removing the wrong wd, due
  to another wd with the same path (self._wd_for_path[src_path] was
  replaced)
- Fix gorakhargosh#117 and gorakhargosh#233
- Still not enough to fix every bug regarding fast/unordered events,
  but doesn't crash anymore

src/watchdog/observers/inotify_c.py

@@ -248,7 +248,8 @@ def remove_watch(self, path):
             Path string for which the watch will be removed.
         """
         with self._lock:
-            wd = self._remove_watch_bookkeeping(path)
+            wd = self._wd_for_path.pop(path)
+            del self._path_for_wd[wd]
             if inotify_rm_watch(self._inotify_fd, wd) == -1:
                 Inotify._raise_error()
 
@@ -322,7 +323,9 @@ def _recursive_simulate(src_path):
 
                 if inotify_event.is_ignored:
                     # Clean up book-keeping for deleted watches.
-                    self._remove_watch_bookkeeping(src_path)
+                    path = self._path_for_wd.pop(wd)
+                    if self._wd_for_path[path] == wd:
+                        del self._wd_for_path[path]
                     continue
 
                 event_list.append(inotify_event)
@@ -387,11 +390,6 @@ def _add_watch(self, path, mask):
         self._path_for_wd[wd] = path
         return wd
 
-    def _remove_watch_bookkeeping(self, path):
-        wd = self._wd_for_path.pop(path)
-        del self._path_for_wd[wd]
-        return wd
-
     @staticmethod
     def _raise_error():
         """