Change method visibility.

Change method addComponent() visibility to public for inheritance.
Add iCal CALSCALE property

Add iCal CALSCALE property and iCal properties variables as constants.
Removed addEvent() method

Removed addEvent() method, now is needed call inherited method
addComponent() from Component class.
Created new component, ALARM
Typo
Add docs comment
Method addComponent() of Component class used.
Recreated addEvent() method and signed it as deprecated
Alarm component added to unit test.
AddComponent() method has been used in examples.
Typo
Merge pull request #20 from elceka/master

Some ideas... :)