Spatialite views

The query logic for vector_layers_statistics and vector_data have been overworked and placed inside the DaoSpatialite class.
DaoSpatialite.checkDatabaseTypeAndValidity now collects all information needed to create the needed SpatialVectorTable for Spatialite4+ Databases.

SpatialiteDatabaseHandler.collectSpatialiteTables will now take of pre-Spatialite4+ Databases, where the bounds must queried for each Table and Geometry Column.

SpatialiteDatabaseHandler.collectVectorTables() has been added that Views and Tables from added from HashMap created in DaoSpatialite.checkDatabaseTypeAndValidity. No queries are needed.
* I have the impression that everything starts quicker than it did before

The Views are correctly recognized, but the SpatialIndex brings no results when called. 
*   I believe this a problem of the created view and NOT the code.
   * since in spatialite_gui the query also brings no results

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Spatialite 4.1.1:
* everything runs correctly with this version as far as I can see, the is no slowing down or any other suggestion that it is causing problems.

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I merged in the changes from master this morning and the Label too show up correctly