[PATCH 0 of 5 STABLE] i18n: some improvements for message translation

[FUJIWARA Katsunori]

This patch series mainly focuses on adding "i18n" comment to:

  - error messages of template functions, and
  - column positioning messages of "hg log" and "hg summary"

Patch #4 and #5 are additional changing around column positioning of
"hg summary" output.

Please drop patch #5, if changing already translatable message is too
close to release.