* cli: move commands to cli/cmd
* cli: use StatusAPI interface for config command
* cli: use SilenceAPI interface for silence commands
* cli: use AlertAPI for alert command
* cli: move back commands to cli package
And move API client code to its own package.
* cli: remove unused structs
* Implement alertmanager cli tool 'amtool'
The primary goal of an alertmanager tool is to provide a cli interface
for the prometheus alertmanager.
My vision for this tool has two parts:
- Silence management (query, add, delete)
- Alert management (query, maybe more in future?)
Resolves: #567
Julius Volz
Simon Pasquier
Frederic Branczyk
Kellen Fox