Fix common spelling error in code and comments

Correct spelling is "incoming" not "incomming".
attrib: Centralize ATTIO connection management

On Generic Attribute, register only one ATTIO connection callback to
centralize the connection management.

Also make sure the connection reference is properly dropped only if
there is no pending operation.
attrib: Discover Characteristics if already connected

On Generic Attribute, Discover All Characteristics of a Service can be
started immediately if already connected, without registering a ATTIO
connection callback.
attrib: Move Characteristic Discovery reply to a new function

Minor cleanup patch moving the creation of the reply for Discover
All Characteristics call to a new local function in the Generic
Attribute.
attrib: Register only new characteristics found

This avoids duplicating registration for previously found
characteristics.
attrib: Fix missing D-Bus message unref on DiscoverCharacteristics

This patch fixes a missing message unref when DiscoverCharacteristics on
Generic Attribute finishes.
attrib: Attempt to remove attio callback on watcher exit

When registering a watcher, it is attempted to add an attio callback.
Therefore, when the watcher is unregistered or exits, this attio should
be removed if there are no other users.

This is already done when unregistering a watcher, it just missed when
it exits without unregistering.
dbus-common: Map GAP Appearance characteristic to icon

Add function appearance_to_icon() to map values from Appearance
Characteristic to icon available.

Note: The Appearance Characteristic is composed of a category (10-bits)
and sub-categories (6-bits). These categories are defined at:
http://developer.bluetooth.org/gatt/characteristics/Pages/
CharacteristicViewer.aspx?u=org.bluetooth.characteristic.gap.appearance.xml
storage: Add storage to GAP characteristic

Add functions to read and write remote Appearance characteristic. The values
are saved in "appearance" file.
device: Appearance characteristic from GAP service

After searching for primary services, the appearance characteristic is
read from GAP service and saved in "appearance" file. Running
GetProperty in device interface, will show the respective icon based in
"appearance" value.
eir: Read GAP appearance from advertising data

This was introduced on Core Specification Supplement (CSS) v1.
Makefile: Add simple-player and test-nap to EXTRA_DIST

Add simple-player and test-nap to the EXTRA_DIST target.
AVCTP: return not-implemented for unknown passthrough
adapter: Fix segfault when icon is uninitialized

If device type is LE and GAP Appearance characteristic does not exist,
the icon will not be initialized.
att: add remote btd_device to ATT read/write callbacks

This allows us to identify the remote device that made the ATT
read/write.
proximity: reporter: save global D-Bus connection

This connection will be used by reporter GATT sub-profiles.
proximity: reporter: move definitions to .h and add util function

This allows us to re-use these definitions in GATT sub-profiles.
proximity: link loss: implement link loss server

The profile is implemented in linkloss.[ch]. A GATT service is
registered with read/write callbacks on the link-loss alert level
attribute. The alert level is maintained per device. It is returned
on read and updated on write.

When the alert level is non-zero, a callback is registered on the
disconnection of the remote device. If a device with non-zero alert
state is disconnected, an appropriate PropertyChanged signal is emitted
with the alert level previously set by the device. We avoid emitting
a signal when the disconnection was requested by us.
proximity: immediate alert: implement immediate alert server

The profile is implemented in immalert.[ch]. A GATT service is
registered with a write callback on the immediate alert level attribute.
This attribute is write-only and is maintained per remote device.

When a remote device write a raises or lowers the alert level,
an appropriate PropertyChanged signal is emitted. When the alert level
of a device is non-zero, a callback is registered on its disconnection.
When the callback is called, the alert level of the device is reset to
zero and an appropriate signal is emitted.
proximity: reporter: implement D-Bus API

Use a device driver to track all GATT supporting devices and register
a D-Bus interface per remote device.

Implement the "GetProperties" method of the D-Bus interface by querying
the alert level of the remote device in the link-loss and
immediate-alert proximity profiles. The default alert level values for
non-connected devices are "none".