Update README.md for v1.1; Closes #9
README: Fix issue links.
Fix typo in TODO comment.
encoder: don't panic on PCM8 / PCM32 inputs

We can instead fallback to the generic implementation for now.
encoder: Add tests; Updates #7
encoder: Document tests more; Updates #7
encoder: Add benchmarks; Fixes #7

BenchmarkDecodeFloat32	     500	  16320072 ns/op
BenchmarkDecodeFloat64	     500	  19265097 ns/op
BenchmarkDecodeUint8	     500	  14820210 ns/op
BenchmarkDecodeInt16	     500	  15722880 ns/op
BenchmarkDecodeInt24	     100	  52042048 ns/op
BenchmarkDecodeInt32	     500	  15294895 ns/op
BenchmarkDecodeALaw	     500	  18334217 ns/op
BenchmarkDecodeMuLaw	     500	  14521286 ns/op

BenchmarkEncodeFloat32	    1000	   6488006 ns/op
BenchmarkEncodeFloat64	    1000	   9089174 ns/op
BenchmarkEncodeUint8	    1000	   9136655 ns/op
BenchmarkEncodeInt16	    2000	   3424256 ns/op
BenchmarkEncodeInt24	    1000	  10707008 ns/op
BenchmarkEncodeInt32	     500	   9236220 ns/op
BenchmarkEncodeALaw	    1000	   8616411 ns/op
BenchmarkEncodeMuLaw	    1000	   7751985 ns/op
Document what types of audio the encoder supports. Fixes #11
decoder: Do not miss a few samples; Fixes #12

The decoder keeps it's current byte count in the data chunk (i.e. how much data
has been read). Previously we advanced this number regardless of whether or not
we had found the data chunk yet (i.e. just reading RIFF information, not audio
samples).

Neatly, this also has all of our decoder tests reading in exactly 90524 samples
compared to the previously incorrect mixed number. The number of samples is not
exactly 44100*2 (1 second of 44100hz 2 channel audio) because the testdata
itself is not precise.
tests: Fix typo pretending ALaw are PCM8 samples. Helps #8

It caused a needless conversion which effectively caused fake benchmark
results for it:

benchmark               old ns/op     new ns/op     delta
BenchmarkDecodeALaw     18507935      14043977      -24.12%
BenchmarkEncodeALaw     9779681       9232771       -5.59%
decoder: Avoid binary.Read / improve performance by 55-88%.

benchmark                  old ns/op     new ns/op     delta
BenchmarkDecodeFloat32     14861757      5489679       -63.06%
BenchmarkDecodeFloat64     16008682      7067748       -55.85%
BenchmarkDecodeUint8       13951858      4908209       -64.82%
BenchmarkDecodeInt16       14685837      5394720       -63.27%
BenchmarkDecodeInt24       50474652      5591962       -88.92%
BenchmarkDecodeInt32       15584887      5472800       -64.88%
BenchmarkDecodeALaw        14637388      4956828       -66.14%
BenchmarkDecodeMuLaw       14626045      4966246       -66.05%

Helps #8
Merge pull request #10 from azul3d/v1.1-dev

Merge v1.1-dev branch into master