CustomCheck was not unique per endpoint address, fixes #58
No caching
Number of endpoints zero'd on SC restart, fixed #20
Merge branch 'develop' into release-1.0.0
Added ability to delete heartbeat for a endpoint
Added way to mute custom checks

Phrasing consistency: events category in plural or singular, fixes #45
Merge branch 'develop' into release-1.0.0
Fixed the problem where the timer only gets executed once.
Making sure the repeated failures are accounted for in the message failures and not just one time failures.
split up message.cs

not sure why there were 8 classes in 1 file
1. Removed Operations folder and moved relevant files under HeartbeatMonitoring

2. Removed Alerts
3. Added EventLog instead.
4. EventLog consists of a generic audit handler that handles IEvents. In order to filter what messages need to be logged in Raven, only messages that contain EventLogDefinitions will be logged.
1. Added a convention to register all messages that start with ServiceControl.Plugin and ends with Messages so that commands from the plugin can be processed automatically

2. Renamed namespaces for the Messages project.
Merge pull request #129 from Particular/alertsCleanup

Alerts cleanup
Merge branch 'release-1.0.0' into develop