Fix Flan, Spud's parts in Astral Charm's quest

Flan and Spud were still referencing quest 5, the old ID of Astral
Charm, instead of the new ID (105).
Disable PVP by default in server.ini
Real skills effects, create StatsComponent

We now use a real skill's effects as defined in Skills.json.
Teleport is implemented separately, since it's main effect (teleporting)
is not described in Skills.json
Other "special" effects not described in Skills.json are not implemented

The skill/battle system isn't finished, it supports:
- Teleporting
- DPS and instant damages
- Targeting (None, Friendly, Self, Ennemies)
- Only the target is affected (by the target and splash effects), the
server does not try to find the untargeted entities affected by the
splash at the moment
- Death/respawning (instantly) for all StatsComponents
- Per-entit base defense stat

This commit also reduces coupling of Widget and Skill, fixes DPS being
mispelled as DSP, takes Duration of effects into account, and fixes mobs
not sending their health stat of 0 when dying.
Process events just before starting the server

The server start will be smoother.
Refactor startServer/stopServer out of widget.cpp
Better message when the server closes
Better message when kicking a player

From the server commands
Bump version to v0.5.3-beta1
Update french translation, translation files