Fixing up the sysmon functionality

- Using the 'Super Simple View Engine'
- Wrapping up the monitoring functionality into a service. This allows
me to use the service as a Singleton (starting performance counters per
request is expensive).
- Unfortunately, Nancy modules are per request scope only - which means
stateful functionality (see above) will need to be wrapped up in a
service. This might make coding a bit more cumbersome for beginners.