Improve Performance

[jcs090218]

The performance depends on the upstream package vc-msg; therefore, it is (almost) impossible to improve performance for this package. I'm thinking of writing my solution, but that requires much work. 🤔 Ideally, it is to swap a backend implementation, but I have not found any suitable replacement on ELPA, MELPA, etc.

Related issues:

• Performance problem on large files/repositories #3