fixes for mncc-harald branch

hi, finally i ported linux-call-router to new mncc api. this is quite easy, because only data types changed. i don't care about change of mncc api from time to time, because openbsc does not have that much applications yet. i think that trau frames don't have anything todo with mncc api and should be use own interface in the future (hopefully with ipaccess). i tested openbsc with linux-call-router. everything worked fine after adding some fixes. now, the mncc-harald includes every work i made, except the installation of library and include files. fix 1: i use this workarround to allow my mobile to get a traffic channel. the mobile reqests a sdcch channel, but currently openbsc is not able to switch channel. (this should be possible in the future for handover.) also it checks if there is actually a traffic channel currently in use, when making a call. fix 2: not actually a fix: adding imsi to gsm_mncc_number allows to notify application about calling/connected imsi. also it is possible to dial a subscriber with no extension assigned, just by using imsi. maybe it is wiser to put imsi string into gsm_mncc, because it is only used only once in a message. fix 3: while detaching, we don't hold a ressource (we don't call lchan_use), so we don't need to "lchan_put". fix 4: the given cause value and location parameters are used in mncc_release_ind function, rather than hardcoded. the plain cause numbers are replaced by the definitions from header file. additionally i uploaded a new inofficial version of openbsc and linux-call-router at www.linux-call-router.de. andreas