Merge pull request #32 from alhardy/dev

Fixed issue with global metrics in owin adaptor
rename json builders
add possibility to attach an existing context
rename json builders
add internal metrics
make json health checks handling consistent with metrics handling
refactor MetricsHttpListener to handle gzip compression
use internal metrics in sample
add endpoint versioned health status
use MetricsDataProvider instead of context
serve flot app gzipped
use metrics data provider instead of context in metrics endpoint
Merge remote-tracking branch 'upstream/dev' into dev

Conflicts:
	Src/Adapters/Owin.Metrics/Middleware/MetricsEndpointMiddleware.cs