Fixed bugs to allow HA to boot again

1) helpers/event should not import the sun component unless it is
requested. This prevents circular import.
2) fixed import typo in bootstrap
2) bootstrap cannot import event_decorators until it is needed because
this leads to a circular import.

homeassistant/bootstrap.py

@@ -24,7 +24,6 @@ import homeassistant.config as config_util
 import homeassistant.loader as loader
 import homeassistant.components as core_components
 import homeassistant.components.group as group
-from homeassistnat.helpers import event_decorators
 from homeassistant.helpers.entity import Entity
 from homeassistant.const import (
     __version__, EVENT_COMPONENT_LOADED, CONF_LATITUDE, CONF_LONGITUDE,
@@ -205,6 +204,7 @@ def from_config_dict(config, hass=None, config_dir=None, enable_log=True,
         _setup_component(hass, domain, config)
 
     # activate event decorators
+    from homeassistant.helpers import event_decorators
     event_decorators.activate(hass)
 
     return hass