Log Message:
Update to version 1.7.0

Changes:

- mkvmerge: enhancement: Added support for MIME type detection via
  libmagic (patch by Robert Millan with heavy modifications by
  myself).

- mkvmerge: bug fix: Theora headers were not handled correctly.

- mkvmerge: bug fix: The WavPack reader was broken on 64bit
  systems (e.g. AMD64).

- mkvmerge: bug fix: The Theora timecode handling was broken, and
  Ogg/Theora files were not identified correctly (they showed up as
  "unknown" in mmg).

- mmg: enhancement: The 'adjust timecodes' function accepts
  timecodes like 'XXXXXunit' with 'unit' being 'ms', 'us', 'ns' or
  's'.

- mkvmerge: enhancement: mkvmerge will no longer refuse to
  concatenate files with differing Codec Private contents and only
  issue a warning in such cases.

- mkvmerge: bug fix: Quicktime/MP4 reader: Added support for
  version 1 media headers ('mdhd' atom) with 64bit fields. Fixed the
  duration of the last packet passed downstream. Fixed overflow
  issues during re-scaling from the Quicktime/MP4's time scale to
  nano seconds used by mkvmerge.

- mkvmerge: bug fix: Muxing wasn't working Windows 9x/ME because
  mkvmerge was trying to use Unicode file access functions when
  determining which directories to create. Fixes Anthill bug #177.

- mkvmerge: new feature: Added support for the "Delay:" feature
  and for negative timecodes in VobSub IDX files.

- mmg: new feature: If mmg is set to automatically fill in the
  output file name then it will clear the output file name once all
  input files have been removed.

- mmg: bug fix: Fixed a crash that occured if the user removed an
  attachment and clicked somewhere in the empty space in the
  attachment list. Occured only on Windows.

- mmg: bug fix: Re-added Chinese to the list of popular languages
  (those are listed first in the language drop down boxes).

- mkvmerge: bug fix: The last change to the ISO 639 language
  handling broke the VobSub reader so that it reported the wrong
  language codes. This also caused mmg to not display the correct
  language after adding a VobSub file.