Fix wrong imports

- "from _compatibility import ..." (not in circular imports)
- "from jedi import builtin" (one of circular imports)
- "api_classes = api.api_classes"
  ("from jedi import api_classes" is not supported)

jedi/evaluate_representation.py

@@ -12,7 +12,7 @@ they change classes in Python 3.
 import copy
 import itertools
 
-from _compatibility import property, use_metaclass, next, hasattr
+from jedi._compatibility import property, use_metaclass, next, hasattr
 from jedi import parsing_representation as pr
 from jedi import cache
 from jedi import helpers