[bug 1098486] Remove under construction page

We never used this, so it's dead code.
Remove more gettext calls

These gettext calls were in the analyzer section (which is not
localized), the services monitor page (which is admin-only) and
the product dashboards which should probaly get nixed soon.
Merge pull request #381 from willkg/1098486-remove-underc

1098486 remove underc
Fix typo and tweak text in new_user_text template
Tweak l10n docs
Fix l10n_status.py script history table

This fixes some issues with displaying the history table so that it
shows up/down movements for highlighted locales correctly.