SQLite provider: Investigate if we can support the new R*Tree SQLite extension

[traianstanev]

SQLite 3.6 introduces a new built-in spatial index functionality in the form of an R*Tree. The spatial index is fully integrated in the SQL semantics of SQLite and spatial (BBOX) queries can in theory execute transparently.

This task is to investigate if the provider can be easily modified to support both its own spatial index and the built-in SQLite spatial index (if it exists). Also, it would be interesting to make a performance comparison between the two.

[traianstanev]

Fixed "Component" field.

[jbirch]

For anyone else looking for information on this new index: ​http://www.sqlite.org/rtree.html