We need an API for this, because otherwise it would be
impossible to start intents and get results from them
without having access to the application's activities.
For third-party libraries etc., this is required.

When we define a public Java API, we will implement a similar
API there, so that applications can also start intents from
Java code without worrying about collisions with third-party
add-ons.

[ChangeLog][Intents] Introduced API to launch intents.

Change-Id: Ic3bbfbbaced3278c2ee970e74cba2997d5d867c4
Reviewed-by: Christian Stromme <christian.stromme@digia.com>