policy: Modify device manager

policy: Modify device manager

Convert some hashmap to idxset for convenience.
Convert some enums to string (device-type, device-role).
Include vconf for get device status.
Separate device-profile from device-type.
Merge some functions which was only for sink or source.
Give same structure(dm_device) when device connected/disconnected.
Apply device mask when get connected device list.
Handle method call GetBTA2DPStatus status.
Ignore duplicated device set-state call.
Fix bug - processed twice when bt-sink loaded.
Fix some bugs.

[Version] 0.5-13
[Profile] Common
[Issue Type] add features and etc.

Change-Id: I17a869ed13d50a8c6bd947e343b593aa7c60e89a
Signed-off-by: Jeongho Mok <jho.mok@samsung.com>