Added a man page, added the (required) scan command (for later extensibility), do syntax checks before super user checks, simplify interface if there's only one device found.

In D3702#244252, @wulf wrote:

IMO, Apple mouse support should be done in other way:

1. Write fake HID descriptor and place it either into bthidd.conf (in textual form) or into bthidctl (in binary form)
2. The descriptor will replace hardwire provided one on bthidctl run, so bthidd will be provided with proper one at start
3. Extend bthidd HID parser to support absolute usages and multitouch to avoid extra apple specific parser.
4. This will reduce size of "if (MAGIC_MOUSE(hid_device) && s->ctx) {}", make it HID-agnostic and provide good start point to write multitouch bt-touchpad/touchscreen support

More spelling fixes from Warren Block.

Spelling fixes by Warren Block.

Incorporate fixes from lme.

Last cleanup broke detection when increasing len variable instead of decreasing it.

Fixing diff to incorporate review by emax

Uploaded new version and replied to comments.

Rename sdp attribute constants to match the SDP_ATTR_ naming convention already in place.

Fix: In sdp.c, int16_t vendor_id, product_id, version were not properly initialised.