[x265] VUI, HRD and SEI

[dave]

Generally, the VUI has two types of fields, those set from the cli and 
those that seem like they should be calculated from the encoding 
process.  At the moment, all the calculated fields only have default 
values.  This includes the bitstream restriction fields, the timinginfo 
stucture and HRD fields.  Some fields are SEI related though I haven't 
had a chance to investigate if they simple reflect the status of SEI 
structures or trigger their encoding.  Unless there is something else 
that needs more attention I can continue working on this.

A couple of other things...

The vui has m_chromaSampleLocTypeTopField and 
m_chromalLocTypeBottomField but I modeled the x265 cli after the x264 
cli which takes one variable and assigns it to both fields.  Is that ok 
or should I add setting each field to the cli?

TComPic has m_conformanceWindow and m_defaultDisplayWindow. Currently, I 
don't think either is used so unless they are needed for future 
development, they can probably be removed.