log speedup: use only ui.write in changeset_printer.show - ui.status is not very useful, since this code is never executed when ui.quiet is true. - explicitly checking for ui.debug allows a regular hg log to run without looking at the manifest index - the calls to ui.note were converted for consistency

adding a
adding b
adding t.h
adding t/x
a
NONEXISTENT: No such file or directory
a
b
t.h
t/x
a: No such file or directory
NONEXISTENT: No such file or directory
b
t.h
t/x
a
NONEXISTENT: No such file in rev ce18e5bc5cd3
a
t/x
b
t.h
% -I/-X with relative path should work
b
t.h
t/x
t/x
t/x