Improve QBluetoothSocket::close() documentation

The disconnected() and stateChanged() signals are delayed which
may easily overlooked by API users. This change specifically points out
this behavior difference.

Change-Id: I3a9e9c656da50c9efe455cd2dbf903a2849e36da
Task-number: QTBUG-41770
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
QBluetoothTransferReply - fix a memory leak.

Fix a potential memory leak in _bluez and _qnx versions of copyToTempFile.

Change-Id: I4c21d25b88620747adaaea8f2da561ca0b3d5df6
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Fix QBluetoothSocket::isReadable()/isOpen()/isWritable()

Change-Id: Ifd6b5ed8176aa7959ed8da0edc762266aa2bd6fa
Task-number: QTBUG-32704
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Fix QBluetoothSocket unit test failures on Android

Change-Id: Ib8800fa30c74678c74df9ed943b143ea4cf49bb2
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Catch segfault when passing 0 to QBluetoothTransferManager::put()

Change-Id: I8c659233fd6eb2232d7bd9d904ce14f1de8a9d34
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Improve QBluetoothTransferManager documentation

Change-Id: I918bd3b4134504d5bfc3e160adeb97187186df3d
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Merge remote-tracking branch 'gerrit/5.4' into dev

Change-Id: I688c8097c167d0ca55106761ceb2712d0c3a796b