VC1: improve frame type detection, even if no entry point is available
QT/MP4 reader: ignore obviously wrong sample size entries
Merge remote-tracking branch 'remotes/brunorex/master'
mmg: fix format string/data type differences with wxWidgets 3.0.0
build system: fix missing space in compiler options if optimizations are enabled
mmg: fix a typo in the »scan directory for other playlists« dialog
translations: update list of translatable strings
common: add template function Is<>() testing EbmlElement for specific classes
common: add function for finding an EbmlElement in an EbmlMaster recursively

Returns both the master and the index at which it was found inside
that master.
mmg: implement drag & drop in the chapter editor

Implements #929.
translations: update list of translatable strings
translations: update German translation
Bump version number, set release code name, add release message
Translations: update Polish