SDK / exoplayer

1. AdtsReader would previously copy all data through an intermediate
adtsBuffer. This change eliminates the additional copy step, and
instead copies directly into Sample objects.

2. PesReader would previously accumulate a whole packet by copying
multiple TS packets into an intermediate buffer. This change
eliminates this copy step. After the change, TS packet buffers
are propagated directly to PesPayloadReaders, which are required
to handle partial payload data correctly. The copy steps in the
extractor are simplified from:

DataSource->Ts_BitArray->Pes_BitArray->Sample->SampleHolder

To:

DataSource->Ts_BitArray->Sample->SampleHolder

Issue: #278