Syntax and some fixes

[tomas]

The most important fixes are:

• Handling a race condition in the fire_callbacks part in agent/providers, that would provoke a specific caller not to get a callback when waiting for a provider.
• Updates the triggers module to 0.0.3, which fixes battery detection on Linux.
• Waits a sec before checking battery status on the 'state_changed' event, that in some cases provoked the power triggers to be fired multiple times.
• Passes a callback to the load_api export in the CP's index.js, that allows passing keys to the api.keys.set() function.