Support default-base-is-moof for demuxing.
print: Print the description of the known brand.

Also add more registered brand FourCCs.
remuxer: Don't pass incompatible brands with the output file format.
dts: Set 31 to CoreLayout when no core substream.

This doesn't make sense for readers since CoreLayout shall be ignored.
But will make sense for the human readability.
dts: Fix the detection of LBR duration modifiers.
dts: Remove unused variables.
remuxer: Pursue the maximum compatibility of 3GPP files.
timelineeditor: Don't pass incompatible brands with the output file format.
remuxer: The referenced chapter track is forbidden to use for 3GPP Basic Profile.
muxer: Fix incompatibility between '3gp6' and '3g2a'.
Remove lsmash_add_free(), lsmash_set_free() and lsmash_write_free().

You can write any Free Space Box at any position without these functions.
box: Write Media Data Box through isom_write_box().
utils: Add 'unseekable' to bytestream handler.
box: Cosmetics around writing Media Data Box.
write: isom_write_{box_name}() doesn't write actually.
Add lsmash_export_box().

This public function export the data of a given box and its children as
the binary string.
read: Read and store fields of unknown boxes as binary string.
hevc: Change the assumption of time_scale.

HM uses time_scale in frame level.
So we follow what HM does.
dts: Take audio presentations into account.

Use the decoder navigation data to seek extension components in audio
assets.
Add parsing core components in extension substreams.
dts: Check the presence of pseudo sync words of X96 extension.