Merge remote-tracking branch 'upstream/master'
- indicate support for OS X
disconnect by server, propagate accept event

disconnect by server: user can force disconnect of client
accept event: user receive accept event to make some actions on it. e.g:
timeout to disconnect client
releasing allocated memmory
removed not needed code
one too many deleted
handling server disconnect if client disconnect already happened
propagate disconnect event to user code

propagate disconnect event to user code
can be used to disable timeout for server disconnect
removed not needed demo-ble.c
- minor changes to pull request (use SIGHUP to signal disconnect, hci_disconnect to disconnect
- update readme with disconnect API
removed not used signal SIGUSR1
handling server disconnect if client not connected
Merge pull request #27 from dragom/master

removed not used signal SIGUSR1
rssi update feature
- minor bracket styling
- add optional callback parameter to updateRssi
- add Linux only updateRssi to Readme
- rename rssi event, fix up OS X exception
- update RSSI on accept on Linux
- uprev version