Use AudioMsgId instead of videoPlayId.
Any audio track now can be a child loader track of some video clip.
Use Type::Voice instead of Type::Video for round video messages.
Video messages play / pause / resume the same way as voice messages.
GIFs get paused if some other layer is displayed above.
Media preview > Box or layer > Saved GIFs panel > Inline bot results.
If any of those is displayed, GIFs inside message history pause too.
Read media information (image / song / video) in SendFileBox in the
same way it is read in FileLoadTask::process() and reuse it in
FileLoadTask if it was loaded already for the box.
Currently the build without implicitly included precompiled header
is not supported anyway (because Qt MOC source files do not include
stdafx.h, they include plain headers).
So when we decide to support building without implicitly included
precompiled headers we'll have to fix all the headers anyway.
Some major platform-dependent file operations refactoring.
All methods like "open file", "open file with", "show in folder"
were moved to core/file_utilities module with platform-dependent
backends. All methods interacting with DesktopServices made async.
