Merge tag '0.2' into develop

Tagged version 0.2
Bumped dev version to 0.3
Improved README, more examples.
Fixed an error message.
Added QuerySet::valuesFlat()
Slightly improved phpdoc.
Added optional param $allowEmpty to QuerySet::single()
Updated changelog
Improvements to code style.
Fixed apigen config.
Updated version for 0.3 release
Merge branch 'release-0.3'