Fix upgrade script

Fix upgrade script

- Add updates directory to store actual upgrade script
- Previous upgrade scripts will determine current version and target version
  and execute proper upgrade script by right order
- Add codes for certificate migration to get dist root to determine privilege level
  because signature file has removed in previous platform for security purpose.
- Certificate values now will be inserted into cert db directly.
- Fix to not to remove shared/data and shared/cache

Change-Id: I52942990115b25d0db489bc4333e6560f978c018
Signed-off-by: Junghyun Yeon <jungh.yeon@samsung.com>