Filip Roséen authored May 09, 2016 and Jean-Baptiste Kempf committed May 09, 2016

matroska_segment_c::Select and matroska_segment_c::Unselect are used to
create/destroy ESs, with that said they are better named ESCreate and
ESDestroy.

Given their name and functionality there is no need (or reason) to send
ES_OUT_SET_NEXT_DISPLAY_TIME from the creator, nor is it necessary to
jump to some particular file-offset (since this is handled by a call to
code that invokes seek in the relevant places).

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>