Soprano Files

Soprano 2.8.0 comes with a bunch of improvements over the 2.7 series, notably:
* Improved NRLModel query prefix expansion.
* Support for plain SQL queries in the Virtuoso backend (required for improvements in Nepomuk).
* Introduced new query language flag QueryLanguageSparqlNoInference. This language is
  not supported by any backends. It is supposed to be used in clients like Nepomuk
  to avoid the usage of long user types which are harder to read.
* Convert Virtuoso IRI_ID values into simple literal strings. At some point if the
  need arises we might call ID_TO_IRI() to convert them into URIs.
* New boolean option "noStatementSignals" in the Virtuoso backend which will disable
  Model::statementsAdded() and friends.
* Improved local unix socket communication in the server/client system:
  A custom socket implementation as a replacment for QLocalSocket makes it possible to
  use one socket across threads.