init: Add quasselcore reload via SIGHUP signal
In brief
- Add support for reloading quasselcore via
SIGHUP- On Quassel 0.13.0+, reloads SSL certificates and other cached info
- Configuration file isn't re-read, but that isn't meant to hand edited
Faux-commit adopted from Ubuntu packaging.
Approval given from Michael Marley (mamarley on Freenode IRC/#quassel).
Edited by Shane Synan