title: Gettext .po files under version control
body: <p>Currently using Gettext on a project and the .po files are nicely kept
  under version control.</p>
  
  <p>PO files of course contain translations, but in addition to that they
  also contain some metadata - information about the exact files and
  line numbers where the translatable strings are located.</p>
  
  <p>The problem is that each time you update the PO files the metadata
  changes a whole lot more than the actual translations.  This makes it
  really hard to later see from version control diff what actually was
  changed - you just see a myriad of changes to file names and line
  numbers.  Like that:</p>
  
  <pre><code>- #: somefile.js:43
  - #: somefile.js:45
  - #: somefile.js:118
  + #: somefile.js:203
  + #: somefile.js:215
    msgid "Translate me please"
    msgstr "Tõlgi mind palun"
  
  - #: somefile.js:23
  - #: somefile.js:135
  + #: otherfile.js:23
  + #: otherfile.js:135
    msgid "Note"
    msgstr "Märkus"
  
  - #: andThatFile.js:18
    #: orThisFile.js:131
  - msgid "Before I was like this"
  - msgstr "Selline olin ma enne"
  + msgid "I happen to be changed"
  + msgstr "Paistab, et mind muudeti"
  </code></pre>
  
  <p>Of course, a simple fix would be to just disable the generation of
  filename/linenumber comments in xgettext output.  But I actually find
  those file names to be quite useful hints when translating.</p>
  
  <p>I surely cannot be the only one who doesn't like the diffs of his PO files.
  Suggestions?</p>