lowmem-governor: Refactor to use the governor independently

lowmem-governor: Refactor to use the governor independently

The governor was modified to use it independently.
 * The lists of apps/procs will be created by lowmem.c, and it will be
   passed to the governor(lowmem_governor_get_kill_candidates).
 * The governor will make an array(candidates) of "filtered and sorted".
   It consists of "struct task_info *".
 * The "struct task_info" was modified to store some informations from
   proc_app_info for governor. Also the pointer of oom_killed from
   proc_app_info was added for the killer.
 * According to the above change, killer of lowmem-controller.c was
   modified.
 * Codes that depend on resourced was removed from governor to lowmem.c.

Change-Id: I1350f2b511d13e3dc7cb1b2efb9e37bc62381275
Signed-off-by: SangYoun Kwak <sy.kwak@samsung.com>