SMS support for osmocombb

[Andreas Eversberg]

hi,

i just finished SMS support for osmocombb. everything is committed in my
jolly/testing branch.

in order to support SMS, i extracted the SMS transcoding from openbsc.
(jolly/sms branch) the SMC and SMR layer protocols are extracted and
rewritten and use messages between layers and have state machines. they
are added to libosmocore also. (jolly/sms branch) openbsc (jolly/sms
branch) now uses the SMS layers and transcoding of libosmocore.

LAPDm now supports correct handling of SAPI 3 datalink, especially on
SACCH. the mobility management and radio ressource layers of osmocombb
now support MM connections with SAPI 3.

i have tested it on test BTS setup only, so feel free to run it and
report bugs.

regards,

andreas