To work in Python 10 and greater

[mlazlo]

To get this to work with a Python 3.10.13 environment I needed to change
v-env/lib/python3.10/site-packages/tornado/httputil.py
this line 25:
From:
import collections
To:
import collections.abc

and also here line 107:

From:
class HTTPHeaders(collections.MutableMapping):
To:
class HTTPHeaders(collections.abc.MutableMapping):