Geopackage-python

Deliverable release for July 15, 2015

What's new:
- Python 3.x support added! Current test platforms are versions 2.7, 3.4, and nightly 3.x releases.
- Geopackage class will now auto-close resources when created in a `with` statement
- TempDB class will now auto-close resources when created in a `with` statement
- Mangled all database connection resources in Geopackage and TempDB classes.

Matrix height and width values in gpkg_tile_matrix did not reflect actual matrix size in some cases. This release fixes the issue.