Sparqlwrapper

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- Returning raw response in case of unknown content type returned
- Fixed some issues with the last version of the SPARQL 1.1 Update Protocol
- setQuery() doesn't imply resetQuery() anymore
- Deprecated addCustomParameter(), addParameter() and clearParameter() come to provide all required functionality
- SPARQLWrapper, QueryResult, Value, Bindings (and classes inherited from them) are new-style classes now
- POST queries are accompanied by full set of parameters now
- Added rudimentary support for JSON-LD
- Added proper unit tests without dependencies of external endpoints
- Fixed Python 3 compatibility issues in SmartWrapper module

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- Implemented update operation according the latest SPARQL 1.1 Protocol drafts (i.e., switching to 'update' parameter)

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- Added the possibility to use two different endpoints for reading and writing operations
- New print_results() function for users testing

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- Update handling 500's coming from SPARQL endpoint (feature request 3198363)
- Added Python 3.x support (feature request 3022722)
- Warning when returned format would be different than the requested one

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- Updated for working with RDFLib3 too (feature request 3117442)
- fixed bug with prefixes' regex (2320024)

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- Supporting keep-alive in SPARQLWrapper if urlgrabber is available (ticket 2929881)
- fixed bugs (2949834)