Use GList instead of custom linked list

Use GList instead of custom linked list

- use GList instead of custom linked list (sync with 2.4)
- remove unused structures:
 registry_x, database_x, layout_x, deviceprofie_x, daemon_x, theme_x,
 font_x, ime_x
- some attributes have just one value(e.g. privilege), so they can be
represented as 'char *' type instead of structure type

Change-Id: If0ba39724664da11ca3f60a48ab535bc936e2397
Signed-off-by: Sangyoon Jang <s89.jang@samsung.com>