This helps to merge similar code from smpp_mirror and smpp_* in follow-up patches.
Related: OS#5568
Change-Id: I8f7ac2c00d16660925dd0b03aa1a0973edf9eb70
As part of preparation for libosmo-netif migration let's move common SMPP code
into separate build-time library and use it for both smpp_mirror and OsmoMSC
renaming the files if necessary.
While at it we also fix id/password legth limits in smpp_mirror and drop unused
fields from ESME struct.
Related: OS#5568
Change-Id: I61910651bc7c188dc2fb67d96189a66a47e7e8fb
Max