Ability to configure long commit warning length

[adamweeks]

It would be nice to configure how long a commit message is before it displays the warning. Some repos I work on allow a 75 char line length, while others allow 100. I know we can enable/disable via git.enableLongCommitWarning config. Would be nice to add one more config for length.

• VSCode Version: 1.8.1
• OS Version: macOS Sierra

Steps to Reproduce:

1. Enter a commit message longer than 50 characters.
2. Observe warning.

[zbjornson]

GitHub shows the first 70 characters and GitLab shows the first 80. Would be nice to have this configurable so users can work to those limits.

[jdforsythe]

I was just about to post this as a request.