Release nodegrind v0.3.0 for node 0.10

- Support SIGINT (ctrl-c) and SIGTERM to terminate the process. This is handy
  for profiling long-running processes.
- Specify the node version supported (0.10). Will push 0.4.0 with explicit
  node 0.11 support as well. In theory, npm should then select the right
  version automatically.