[push-forwarder] Split WSP payload

Instead of sending the whole WSP datagram to the handler we now send
content type string and WSP payload data. This way push handler won't
have to parse WSP headers just to extract the payload.
[rilmodem] Refine SMS sending response value handling

By this change, the SMS is resent only  in cases it is worth of retrying.

Signed-off-by: Petri Takalokastari <petri.takalokastari@oss.tieto.com>
Merge pull request #179 from ptakalok/mosms

[rilmodem] Refine SMS sending response value handling
Merge pull request #180 from monich/split_wsp_payload

[push-forwarder] Split WSP payload
[rilmodem] Mobile country code configuration

Enable limiting radio technology based on mobile country code found
from ICC.

Signed-off-by: Jussi Kangas <jussi.kangas@oss.tieto.com>
[configure] Make the push-forwarder plugin configurable

Signed-off-by: Martti Piirainen <martti.piirainen@oss.tieto.com>
Merge pull request #183 from marttipiirainen/next

Make the push-forwarder plugin configurable
[configure] Make libwspcodec dependency conditional

Signed-off-by: Martti Piirainen <martti.piirainen@oss.tieto.com>
Merge pull request #182 from jkangas/next

Request for pulling tech pref config possibility based on mobile country code to next branch
Merge pull request #185 from marttipiirainen/next

Make libwspcodec dependency conditional
[src] Fix EF_PNN access

EF_PNN was not being read properly, which affected the displayed PLMN
name for some MVNOs. Some modems already read the file and return the
right string: these do not show the problem.
Merge pull request #188 from jkangas/next

Request for pulling EFPNN 7-bit unpacking before trying convert it to UTF8 to next branch