{lib}mediainfo-gui: 0.7.78 -> 0.7.79

Following a commit by @k0ral, this completes the upgrade of the other
`mediainfo` components.

From the changelog:
```
Version 0.7.79, 2015-11-02
+ CLI/DLL only, XML: new option --Output=MIXML, with XML v2.0beta1
  status, not for production, see
  https://github.com/MediaArea/MediaAreaXml for more details
+ MediaTrace: support of more than 1 file in XML output.
+ CLI/DLL only, XML: new option --Output=MAXML, with XML v0.1 status, in
  order to have bot MediaInfo and MediaTrace in the same output, not for
  production, see https://github.com/MediaArea/MediaAreaXml for more
  details
x MediaTrace: fixed some invalid outputs
x #B951, Amazon S3 support (REST API v2), CLI/DLL only and if compiled
  with libcurl support: URL without credential were badly interpreted
```