Please do not create strings untranslatable with Transifex

In [ https://gitweb.torproject.org/torbutton.git/blob/HEAD:/src/chrome/locale/en/aboutTor.dtd#l26] aboutTor.dtd one can currently find:

<!-- Note to translators: the following 18 entities are used to construct a
   - sentence (either the SP or DDG entities are used, but not both at the
   - same time).   In English, the sentence reads:
   -    Search securely with Startpage.
   - or:
   -    Search securely with DuckDuckGo.
   - The sentence contains two embedded links for "securely" and
   - the search engine ("Startpage" or "DuckDuckGo").
  -->

That's really, really not the way to do it. Isn't there an equivalent to sprintf for Firefox extensions?

The following strings can't be translated properly with Transifex:

<!ENTITY aboutTor.searchSP.privacy.beforeLink.label "Search ">
<!ENTITY aboutTor.searchDDG.privacy.beforeLink.label "Search ">
<!ENTITY aboutTor.searchSP.search.beforeLink.label "with ">
<!ENTITY aboutTor.searchDDG.search.beforeLink.label "with ">

The ending space is invisible in any graphical translator (e.g. Transifex, our recommended tool for translators). :(