Hello,
As a competition, I suggest po4a add 'translator-credits' support.
po4a-updatepo will generate 'translator-credits':
    #: ../source/book.xml:0
    msgid "translator-credits"
    msgstr ""
    "alice <alice(a)example.com>, 2005-2008\n"
    "bob <bob(a)example.com>, 2005,2008"
if the source xml have info (bookinfo|articleinfo|info) element,
po4a-translate will
add 'othercredit' and 'copyright' like this:
    <othercredit class="translator">
      <firstname>alice</firstname>
      <email>alice(a)example.com</email>
    </othercredit>
    <othercredit class="translator">
      <firstname>bob</firstname>
      <email>bob(a)example.com</email>
    </othercredit>
    <copyright>
      <year>2005</year>
      <year>2006</year>
      <year>2007</year>
      <year>2008</year>
      <holder>alice <alice(a)example.com></holder>
    </copyright>
    <copyright>
      <year>2005</year>
      <year>2008</year>
      <holder>bob <bob(a)example.com></holder>
    </copyright>
Any comment?
Best Regards,
-- 
Dongsheng Song