Force merge conflicts

[craffel]

Force merge conflicts

[blester125]

I've start to explore making a merge tool.

I have created a simple text-based proof to concept to explore how custom merges are defined and how they interact with clean filters.

Lucky for us the file contents at %O %A %B (the temporary files the merge tool can look at) are the cleaned files. This will make merging a lot easier for us.

My plan is to create a simple tool (based on prompt-toolkit) that iterate through the parameter groups that have been changed and asks the user how to merge them. I plan to have the actual merging operations be done via plugins that can get auto-added to the option list but I want to start with take A, take B, keep Original and average.

Eventually it would be cool to add extra, nesting aware options like apply merge to module where the same action (take A, avg, etc) is applied to all the parameters within a scope like .../encoder/layer_\d/attention i.e. to q,k, and v, etc. Similarly you could have an apply to layer action or an apply to all action. This would be added later though.