CURRENT, usr/src on git, howto "mergemaster"?

Now, since /usr/src has been siwtched to git on several boxes and the former svn tag
$FreeBSD$ seem not valid/useful anymore, how am I (or any other here) supposed to
"mergemaster"?

I did a full "mergemaster -CUFi" lately and did the same again, but when mergemaster ran
the second (or n-th) time again, it stops by by the same non standard files in etc edited
by me. Is there a workaround and if so, please hint me to the announcement. 

Thanks in advance,
a happy new year

oh