Manage loader slot state

Manage loader slot state

Adds new attributes of loader for managing loader slot state:
 - TTL (minutes): Denote timeout value for DEACTIVATION_METHOD.
 - ACTIVATION_METHOD: REQUEST and AVAILABLE_MEMORY methods are available.
 - DEACTIVATION_METHOD: TTL and OUT_OF_MEMORY methods are available.

After this patch is applied, loaders are managed by two states(running or paused).
When the loader is paused, the launchpad cannot make candidate process.
And, if the candidate process is running, it will be disposed.

Change-Id: I7de4f28e513aefb022a51f30e974d7f481053bdd
Signed-off-by: Hwankyu Jhun <h.jhun@samsung.com>