Changelog:
===========
* Bug fix: Overburning with cdrskin option -force ended by a libburn error
* New API call burn_write_opts_set_bdr_obs_exempt()
* New cdrskin option --bdr_obs_exempt
* Officially enabled overburning with burn_write_opts_set_force(,1)

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>