Log Message:
Changes 0.6.20:
* New translations: bs, tr
* Updated translations: be, cs, da, de, en_GB, en_CA, it, ja, nl, pl, pt_BR,
  pt, ru, sk, sq, sr, sv, vi, zh_CN
* Fixed some problems in the write-exif.c example program
* Stop listing -lm as a required library for dynamic linking in libexif.pc
* Turned on the --enable-silent-rules configure option
* Changed a lot of strings to make the case of the text more consistent
* exif_entry_dump() now displays the correct tag name for GPS tags
* Fixed some invalid format specifiers that caused problems on some platforms
* Display rational numbers with the right number of significant figures