Avidemux 2.6.13

[baziroll]

[2.6.18 Nightly 2017-01-11]

[delogo] Add a small helper symbol
Merge branch 'master' of github.com:mean00/avidemux2
[delogo] Display help image, incomplete
Merge pull request #69 from eumagga0x2a/set-audio-codec
[delogo] cleanup ui
[UI] Preserve audio codec upon loading a video, now for real
Merge branch 'master' of github.com:mean00/avidemux2
[mpdelogo] Keep old UI for the moment
[delogo] Refresh of UI, WIP
Merge pull request #66 from TotalCaesar659/master
[build] Not release anymore

2017-01-06: 2.6.18 : "Exactly worth what you pay for it".

* Preview : Fix auto resize when video has ~ same dimension as screen*
* Preview : Fix multiple preview breaking navigation
* Preview : Fix slider and tooltips (euma)
* Mp4/Mp4v2: Allow E-AC3 (fiftyplus/euma)