update changelog.
generated pot file

Current one is very old. All po files should be merged with this new pot file.
updated for new pot file
only set If-Modified-Since header if lastmodified != 0.
Merge branch 'master' of github.com:akrennmair/newsbeuter
Merge pull request #100 from donnut/master

update pot and nl.po fle
merge .po files with new .pot file.
fix fuzzy strings in de.po file.
reuse old google_api.h file.
add support for theoldreader.com.
Merge branch 'master' of git://github.com/akrennmair/newsbeuter

* 'master' of git://github.com/akrennmair/newsbeuter:
  add support for theoldreader.com.
  reuse old google_api.h file.
  fix fuzzy strings in de.po file.
  merge .po files with new .pot file.
  only set If-Modified-Since header if lastmodified != 0.
  updated for new pot file
  generated pot file
  update changelog.