Refactoring of AnalyzerResult in order to address issue #13

Add AnalyzerAttributes to handle the metadata in AnalyzerResult and store the Analyzer parameters
Attributes include :
- [x] sampleRate, blockSize, stepSize
- [ ] version of the analyzer (or Timeside release ?)
- [ ] audio source file name
- [x] analysis parameters
- [ ] precision of the results data (float, long, ...)
- [ ] stereo / mono / left / right channel management during analysis ?

AnalyzerResult now include a @property field "properties" containing a dictionnary of the following stats about the results data :
- mean
- median,
- std
- min
- max

Also change the result value return by AubioTemporal because mean and median are now include in "properties"
Merge branch 'dev' of https://github.com/yomguy/TimeSide into dev
 * fix some variable names fot overhaul coherence
 * fix yafee.results container
Fix isssue in AnalyzerResultContainer representation
Change 'Attributes' to 'Metadata' in AnalyzerResult
Create MetadataObject as a generic class to handle Metadata
Fix issue in Yaafe analyzer

Yaafe setup was overwriting self.blocksize() and self.samplerate() instead of self.input_blocksize and self.input_samplerate
grapher: PIL modules by default
README.rst: fix typos
timeside/static: remove executable bit
Add New Metadata fields (data, idMetadata, audioMetadata, frameMetadata, labelMetadata, parameters) structure to be included in AnalyzerResult
Add new structure for the analyzerResult + Add Analyzer generic processor

Add a new structure to handle the different kind of metadata :
 - data
 - idMetadata
 - audioMetadata
 - frameMetadata
 - labelMetadata
 - parameters

Automatic setting of some metadata is providing through a generic Analyzer processor class from which the common analyzer derives.

Modifiy setup() parameters for all processors to diffenriate between source_* parameter and input_*, output_* parameters for the non-source processors
Refactoring of AnalyzerResult in order to address issue #13

Add AnalyzerAttributes to handle the metadata in AnalyzerResult and store the Analyzer parameters
Attributes include :
- [x] sampleRate, blockSize, stepSize
- [ ] version of the analyzer (or Timeside release ?)
- [ ] audio source file name
- [x] analysis parameters
- [ ] precision of the results data (float, long, ...)
- [ ] stereo / mono / left / right channel management during analysis ?

AnalyzerResult now include a @property field "properties" containing a dictionnary of the following stats about the results data :
- mean
- median,
- std
- min
- max

Also change the result value return by AubioTemporal because mean and median are now include in "properties"
 * fix some variable names fot overhaul coherence
 * fix yafee.results container
Fix isssue in AnalyzerResultContainer representation
Change 'Attributes' to 'Metadata' in AnalyzerResult
Create MetadataObject as a generic class to handle Metadata
Add segment support to the decoder through GNonLin

Segment 'start' and 'duration' should be passed during the decoder setup.
If omitted, it keep the original behavior.
Fix issue in Yaafe analyzer

Yaafe setup was overwriting self.blocksize() and self.samplerate() instead of self.input_blocksize and self.input_samplerate
Fix gstreamer caps issue in decoder core related to Gnonlin

Gnonlin gnlurisource needs the fields 'start' and 'duration' to be set to be abble to query the duration of the segment