I'd invite you to check out an app I made for that sort of thing - though you aren't able to see who made the change*. If you aren't able to use something like subversion an option is to use REST calls but that will only return the current configs. The main thought behind my app was to run the REST searches once a day which allows you at least to see what has changed over a period of time - new things, deleted things, changed things.
This looks good. Will i be able to see what exact changes where made in a search syntax of a saved search?
And is this compatible with 6.3?
There is a dashboard that will show the new and old search side by side but won't highlight the specific changes. I should note though that it will only be able to show changes going forward from when you installed it. Haven't tested it with 6.3 as I'm not using that version. In theory it should work.
I've just had a look at that app and it seems as if there might be some corruption/unintended files inside the app. Every single directory contains paxheader directories.
Pax is a compression format, but not all Windows compression utilities handle it well and they create those paxheader folders when you uncompress some files. You can just delete them usually.