Merge branch 'dbtests' into merge

* Remove function get_binary_components().
* Test and refactor get_component_by_package_suite().
* Convert class Component to ORMObject.
* Drop class BinAssociation.
* Create, test, and refactor get_suite_version_by_package().
* Create, test, and refactor get_source_by_package_and_suite().
* Remove unused function get_binaries_from_source_id().
* Remove unused function get_binaries_from_name().
* Remove unused function get_binary_from_id().
* Test and refactor function add_deb_to_db().
* Refactor and test class DBBinary.

Signed-off-by: Torsten Werner <twerner@debian.org>