Added Polish translation
Add Polish translation
Merge pull request #110 from raven700/master

Add Polish translation
Drop unused class forward declaration
Fix indent level
Rename Greeter::process to m_process

All other members are called this way.
Get rid of qobject_cast where possible.

If a class assumes parent to be of known type, state it explicitly in the
sources.
Merge pull request #112 from urkud/cleanup

Clean up.