Migrate over to using pyosmocom

We're creating a 'pyosmocom' pypi module which contains a number of core
Osmocom libraries / interfaces that are not specific to SIM card stuff
contained here.

The main modules moved in this initial step are pySim.tlv, pySim.utils
and pySim.construct. utils is split, not all of the contents is
unrelated to SIM Cards.  The other two are moved completely.

Change-Id: I4b63e45bcb0c9ba2424dacf85e0222aee735f411

pySim/ts_31_103.py

@@ -23,16 +23,16 @@ Various constants from 3GPP TS 31.103 V18.1.0
 #
 
 from construct import Struct, Switch, this, Bytes, GreedyString
+from osmocom.utils import *
+from osmocom.tlv import *
+from osmocom.construct import *
 from pySim.filesystem import *
-from pySim.utils import *
-from pySim.tlv import *
 from pySim.ts_51_011 import EF_AD, EF_SMS, EF_SMSS, EF_SMSR, EF_SMSP
 from pySim.ts_31_102 import ADF_USIM, EF_FromPreferred
 from pySim.ts_31_102_telecom import EF_UServiceTable
 from pySim.ts_31_103_shared import *
 import pySim.ts_102_221
 from pySim.ts_102_221 import EF_ARR
-from pySim.construct import *
 
 # Mapping between ISIM Service Number and its description
 EF_IST_map = {