QtSignalForwarder: use full name QObject::connect

Signed-off-by: Branislav Katreniak <bkatreniak@nuvotechnologies.com>
QtSignalForwarder: add support for context in signal connections

This matches new QObject::connect syntax in qt 5.2

Signed-off-by: Branislav Katreniak <bkatreniak@nuvotechnologies.com>
Merge pull request #4 from katreniak/bka-signalContext

Add optional context parameter to bind() calls