Opus 1.0.2 release

Opus 1.0.2 fixes an out-of-bounds read that could be triggered by a malicious
Opus packet causing an integer wrap-around in the padding code. Considering
that the packet would have to be at least 16 MB in size and that no
out-of-bounds write is possible, the severity is very low. This new release
also has the following changes:

== Quality-impacting ==
* Changed the behaviour of the PLC to always fill the caller's buffer
* Properly decode in-band FEC for packets with mutiple Opus frames
* Hybrid mode quality improvements and fixes
* Fixed bugs in the CELT mode PLC
* Redundant mode transition fixes

== Other changes ==
* Stack reduction
* Doc fixes (many)
* 16-bit fixes
* Misc build fixes
* New API calls: OPUS_GET_LAST_PACKET_DURATION ctl() and
  opus_packet_get_nb_samples()
* Minor code cleanup
This tag has no release notes.