Move the code from pySim-smpp2sim.py to its own file, so it can be properly
extended.
The current file parses argv, opens a reader and starts the Twisted
reactor at import time, so nothing else can import it.
No functional changes yet, improvements follow in later commits.
Change-Id: Ifd8a15684939977d29ea83a6b669daee14484e88
The pySim-smpp2sim.py program exposes two interfaces:
* SMPP server-side port, so external programs can rx/tx SMS
* APDU interface towards the SIM card
It therefore emulates the SMSC, Core Network, RAND and UE parts
that would normally be encountered in an OTA setup.
Change-Id: Ie5bae9d823bca6f6c658bd455303f63bace2258c