Bluetooth: Implement a more complete adapter initialization sequence

Using the managment interface means that user space doesn't need to do
any HCI command sending at all. This patch moves the remaining
initialization commands from user space to the kernel side. The patch
makes use of the new feature of __hci_request which allows the request
to be dynamically modified while it is ongoing (something that is needed
to react appropriately to the local features and the version of the
adapter).

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>