preventing a dot in key breaks applications

This shall be an optional config parameter, but having this constraint hard-coded, makes current apps which worked with previous versions without issue, break.

Author: Tzury Bar Yochay

bson/__init__.py

@@ -349,8 +349,8 @@ def _element_to_bson(key, value, check_keys, uuid_subtype):
  if check_keys:
  if key.startswith("$"):
  raise InvalidDocument("key %r must not start with '$'" % key)
- if "." in key:
- raise InvalidDocument("key %r must not contain '.'" % key)
+ # if "." in key:
+ # raise InvalidDocument("key %r must not contain '.'" % key)
 
  name = _make_c_string(key, True)
  if isinstance(value, float):