In encoder, when automatically selecting profile, choose a still
picture profile when the level is 15.5 and a single picture is to
be encoded.
In decoder, don't check for single picture constraint when looking
up profiles.

Align software with specification fix #1247

CPB changes impact 8K levels; MinCRScaleFactor for 4:4:4 profile.

Renumbering level according to major*16+minor*3, with maximum level now
15.5 (not 8.3).

Added main_10 and main_444_10 profiles, and removed old profiles.
Use 'auto' to automatically select (changed default of cfg files).
Use 'none' to produce non-conforming bitstreams.

Also added a structure that describes the features of each
profile/level/tier, should be added as further constraint checks added.