timeline: Fix possible NULL dereferences when getting the closest RAP.
timeline: Fix possible NULL dereferences when copying timeline map.
vc1: lsmash_create_vc1_specific_info() requires both seqhdr and ephdr.
dts: Handle reserved box field properly when absent in the source.
importer: Place ISOBMFF/QTFF importer after the all other importers.

There are possiblities of false positive of size field which could cause
large memory allocation because of unknown types of box until close of
impoter.
description: Fix a memory leak when color table which shall be present is absent.
adts_imp: Fix a memory leak when failing to parse ADTS headers.
mp3_imp: Fix a memory leak when failing to create/allocate a new summary.
isobmff_imp: Fix a possible NULL dereference when getting summary.
print: Remove redundant NULL check for lsmash_file_t pointers.
print: Error handling when lsmash_fopen() failed.
description: Check size is valid or not when constructing 'glbl'.
mp4a: Enclose intentional dead code with #if 0.
isom: Avoid NULL dereference when getting a data reference entry to write.
timeline: Avoid NULL dereference when evaluating sample description.
write: Avoid NULL dereference when remenbering position of 'elst'.
lib: Support Opus-in-ISOBMFF.

Don't distribute generated Opus-in-ISOBMFF files.
It is highly experimental stage at present.