namespace: introduce logfmt to show l10n-ed messages for hg log correctly
Before this patch, "_()" is used incorrectly for "tag:" and
"bookmark:" fields. "changeset_printer()" looks up keys composed at
runtime, and it prevents "xgettext" command from getting strings to be
translated from source files.
Then, *.po files merged with updated "hg.pot" lose msgids for "tag:"
and "bookmark:".
This patch introduces "logfmt" information into "namespace" to show
l10n-ed messages "hg log" (or "changeset_printer()") correctly.
For similarity to other namespaces, this patch specifies "logfmt" for
"branches" namespace, even though it isn't needed (branch information
is handled in "changeset_printer()" specially).
To find related code paths out easily, this patch adds "i18n: column
positioning ..." comment to the line composing "logfmt" by default,
even though this line itself doesn't contain any strings to be
translated.
http://example.com/no/anchor, branches: (None, [])
http://example.com/an/anchor, branches: ('foo', [])
http://example.com/no/anchor/branches, branches: (None, ['foo'])
http://example.com/an/anchor/branches, branches: ('bar', ['foo'])
http://example.com/an/anchor/branches-None, branches: ('foo', [])
http://example.com/, branches: (None, [])
http://example.com/, branches: (None, [])
http://example.com/, branches: ('foo', [])