Since I want to add comments in the code while I browse through the code making small modifications, basically getting accustommed to it, I was thinking about the possible solutions to this case:
* add the comments in my local working copy, then preprocess somehow the source files to strip the comments just before commit. I'm not sure how this will work when pulling/updating from the repo.
* An editor/IDE that have the ability to keep the comments separately as metadata and show them nicely for view/edit in its editor windows. Havent't found any still...
A similar question: http://stackoverflow.com/questions/1856133/separate-code-and-comments