Map handling neg

[mmehta2669]

Description

added changes for maps to handle negative values

Fixes #1205

Type of change

(Check the ones that apply by placing an "x" instead of the space in the [ ] so it becomes [x])

• Note merging this changes the database configuration.
• This change requires a documentation update

Checklist

(Note what you have done by placing an "x" instead of the space in the [ ] so it becomes [x]. It is hoped you do all of them.)

• I have followed the OED pull request ideas
• I have removed text in ( ) from the issue request
• You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

Limitations

N/A