Added Bluez 5.x support

    New cmake option PSMOVE_BLUEZ5_SUPPORT.
    If it's enabled, linux_bluez_register_psmove() calls
    linux_bluez5_register_psmove(), which fills /var/lib/bluetooth
    according to Bluez 5.x rules.
    Added automatic detection of init system type (systemd, upstart,
    sysvinit) and used appropriate bluetooth daemon start/stop commands
    for each type.
Fixed according to review comments.

Replaced multiple malloc-strcpy-strcat calls with
single function bt_path_join().
Corrected /etc/os-release handling.
Merge pull request #102 from MooseTheBrown/bluez5_support

Added Bluez 5.x support