tests/test-revlog-packentry.out

Make {file_copies} usable as a --template key

Before this, to display file copies in templates, you had to write something
like {file_copies%filecopy}. For some reason, the {file_copy} subtemplate was
used by default but not defined by default in changeset_templater, while styles
were already using it. Here we define {file_copy} in changeset_templater, and
change the templater to handle formatting strings like {file_copies%filecopy}
with already expanded keys (in this case {file_copies}), for backward
compatibility.

adding foo
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
adding foo
created new head
   rev    offset  length   base linkrev nodeid       p1           p2
     0         0       0      0       0 b80de5d13875 000000000000 000000000000
     1         0      24      0       1 0376abec49b8 000000000000 000000000000