Modernize Qt connections

First commit of modernizarion of Qt signal connections,
the new signal connection is very userfull because of a few
nice things:

- it's checked at compile time instead of runtime
- it can connect to any function or method, so we don't need
to use slots anymore
- it's way faster because it doesn't need to work with string
comparisson, but it's basically a direct call.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>