android/pan: Fix control state change callback parameters order

Callback declared in bt_pan.h is
'typedef void (*btpan_control_state_callback)
(btpan_control_state_t state, bt_status_t error, int local_role,
const char* ifname);

But PanService.Java defined it wrong way.
private void onControlStateChanged(int local_role, int state,
int error, String ifname).
First and third parameters are misplaced, so sending data according
to PanService.Java, discard this fix if issue fixed in PanService.Java.
android/pan: Handle error case properly in NAP registration
android/pts: Add PTS test results for AVRCP
android/pts: PTS test results for A2DP
android/pts: PTS test results for DID
android/pts: PTS test results for GAP
core: Fix rejecting ATT packets greater than the negotiated MTU
[travis-ci] Add configuration file
android: Fix GNU old-style struct field designator

This gives a warning on clang, that turns into an error due to -Werror.
attrib-server: Remove unnecessary fields from struct gatt_channel

These fields are only used internally by attrib_channel_attach(). The
"No GATT server found..." error message was also removed as it is also
displayed by find_gatt_server().
core: Fix associating a GAttrib to a device on incoming connections

If BlueZ is running as slave, incoming connections using ATT CID will
have a GAttrib created for them. But this GAttrib will not be assigned
to the underlying device (whose struct btd_device instance was created
in response to the Device Connected mgmt event).

This patch fixes this by assigning the GAttrib to the btd_device as soon
as a connection is first requested, which is done using attio callbacks.

Note that a new GAttrib reference is taken because attio callbacks "own"
device->attrib and thus need their own reference.
alert: Only remove attio callback after ATT request was sent

If there is a single registered attio callback, any pending ATT requests
will be dropped as soon as it is removed. This commit makes sure that
the request is sent before removing the callback.

Other places using attio callbacks may need fixing as well.