Clear all Recents apps and mem usage in Recent apps

Clear all Original code by PA D4rKn3sSyS

Screenshot is here:
https://www.dropbox.com/s/vqtmf431juv17ct/Screenshot_2013-01-14-23-48-45
.png

Signed-off-by: htchoi1995 <htchoi1995@gmail.com>