Add new attribute to get gdbus connection from outside and etc.

Add new attribute to get gdbus connection from outside and etc.

1. gdbus connection will be always created when handle created,
but, sometimes, g_bus_get_sync got crashed.
So, muse server will get gdbus connection once at start time,
module will use it without getting gdbus connection.
2. RM related code modified.

[Version] 0.10.85
[Profile] Common
[Issue Type] Update
[Dependency module] N/A
[Dependency commit] N/A
[Test] [M(T) - Boot=(OK), sdb=(OK), Home=(OK), Touch=(OK), Version=tizen-mobile_20161024.2]

Change-Id: Id680ffbbcdb6213026898d226be7853359f9624a
Signed-off-by: Jeongmo Yang <jm80.yang@samsung.com>