Output the libav codec and bit rate in audioloader

This is so that other algorithms can report or use this information.
Not implemented for standard mode, and the the outputs must be
directed somewhere - I'm not sure if this can be made optional
Update music extractor to add codec, bitrate, file name metadata
Put filename in metadata:tags not metadata:audio_properties
also quote key names when outputting json

In normal situations when exporting json a key shouldn't need to
be quoted, but sometimes user-provided data is serialised, for example
tags from taglib take both the key and value. On flac files this key
can be user-provided and therefore a bad key can create invalid json
Allow only specific examples to be compiled

In order to not change the existing behaviour of --with-examples,
this adds a new option that you can use instead:

  ./waf configure --with-example standard_mfcc,streaming_gfcc

Will build only the specified examples. You can specify one or more.
To compile all examples, use

  ./waf configure --with-examples

as before. If we are happy to change the behaviour of this option we
could require an argument such as 'all' to compile all examples.
optparse does not support an option that can have an optional argument,
so we cannot keep the existing behaviour.
Add optional 'indent' parameter to json output

Indent controls how many spaces are used to indent each
json block. If indent is > 0, newlines and indents are added.
If indent == 0, the json document is output on a single line
Don't add extra extension to the output filename (#156)

Because you can now specify - as output to send to stdout, write logging
to stderr (fixes #157)
Increase buffer size "forMultipleFrames" because ChordsDetection would fail on very long audio
Merge pull request #167 from MTG/optionalexamples

Allow only specific examples to be compiled
Tests for streaming audioloader, pass codec, bitrate to standard loader
fogot to connect new md5 sink in several extractors
Connect AudioLoader codec and bit_rate to NOTHING in examples
Set sampleRate parameter to analysis sample rate for EqualLoudness algorithm

Default 44100 value for sampleRate may not always correspond to the analysis sample rate specified by user in a profile file.
Updated a check for denormalized values. Fixes occasional Inf values in EqualLoudness. Closes #160

Previosly this check was manually implemented and worked only for i386 and floats. Using std::fpclassify instead. This
solves the issue of Inf values in EqualLoudness algorithm output, and the consequent issue of Nan values in Spectrum
which was causing an infinite loop in SpectralPeaks.
Add lossless flag and option to quit if no mbids

The lossless flag is set if the ffmpeg codec is one of a known
set of lossless codecs.
If the option 'requireMbid' from the profile file is true, the
extractor will quit early if there is no 'musicbrainz_trackid'
tag in the file being processed
Merge branch 'master' into audioloader-codec

Conflicts:
	src/examples/streaming_onsetrate.cpp
	src/examples/streaming_panning.cpp
Merge branch 'audioloader-codec'
Install version.h

Fixes #137
Fixes #168
Throw a correct error if the file has no extension
Merge pull request #173 from MTG/jsonoutput

Jsonoutput