[Lazarus] GIT sha1 vs svn numbers

[Martin Frb]

I looked at a few ideas, if something like the svn numbers could be 
retained.

One approach would be to have a tag on each commit. That would mean that 
r54123 would be a replacement for the sha1 in almost all (if not all)  
situations.
Not tested, but likely that the server can add the tags, when stuff gets 
pushed.
The downsides:
-  might slightly slow down "git log" (not much really)
- "git tag" which usually lists tags like releases, will list 50000+ 
revisions too
   viewing tags in GUI frontends may take serious time, as GUI frontends 
seem not to expect this (tested with tortoise / tortoise revision graph 
even crashes with that)
- may interfere otherwise when tagging releases etc / need to push new 
tags individually by name.


Another approach would be to include such info in the commit-message.
But that has to be done with the commit. That is locally by each user. 
(by a local git hook script).
Therefore those refs would not be unique. Duplicates are possible.
This is similar to the "git-svn-id" present in the commit message of all 
imported commits.