git-svn: log command fixes

git-svn: log command fixes

Change the --verbose flag to more closely match svn.  I was
somehow under the impression that --summary included --raw diff
output, but I was wrong.  We now pass -r --raw --name-status as
arguments if passed -v/--verbose.

-r (recursive) is passed by default, since users usually want
it, and accepting it causes difficulty with the -r<revision>
option used by svn users.  A --non-recursive switch has been
added to disable this.

Of course, --summary, --raw, -p and any other git-log options
can still be passed directly (without --name-status).

Also, several warnings about referencing undefined variables
have been fixed.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>