Handle port collisions
Handle port collisions

When the TCP port that NIPAPd listens to is already in use, an ugly
exception was thrown. That is now handled in a bit more gracious manner
- with log message and all. Given the exception, there could probably be
other reasons that we cannot start listening than just the port being
occupied...

Fixes #124

plajjan/NIPAP,plajjan/NIPAP,plajjan/NIPAP,garberg/NIPAP,bbaja42/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,garberg/NIPAP,fredsod/NIPAP,ettrig/NIPAP,ettrig/NIPAP,plajjan/NIPAP,SoundGoof/NIPAP,bbaja42/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,garberg/NIPAP,bbaja42/NIPAP,plajjan/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,fredsod/NIPAP,garberg/NIPAP,ettrig/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,fredsod/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,plajjan/NIPAP,SpriteLink/NIPAP,fredsod/NIPAP