I have a problem with saving different config files in my `Mercurial` repository. For example, I have 2 branches - `dev` and `testing`. For each, I have my Jenkinsfile (configuration of Jenkins pipeline). It also could be any other configuration files (DB config, other systems configs) that are different between branches. Each time when I merge `testing` with `dev` I should merge the Jenkinsfile manually. How could I solve this problem? I wanna save the history of my config files and don't wanna have any problems with merging. Is there any approach to solve this routine problem?