Manipulate checks via stalker-client

Fixes #19. Lets stalker-client:

- List checks for a given host/ip
- Remove all checks for a given host/ip
- Initiate a recheck for given check id

stalkerweb now returns the checks _id field in all cases.
Merge pull request #20 from pandemicsyn/sc-enhancements

Manipulate checks via stalker-client