[PATCH] SAP client

I have now committed the attached patch to remotes/origin/nion/sap. I've used this so far in combination with the sap server in the softsim repository in order to not use the sim driver. The patch removes the pre-defined sap socket path and additionally to the already existing config option introduces a new vty command to set the socket before issuing sap reader ms... Andreas told me that the initial plan was to implement the sap server in osmocom as well and also speak to the sim into the phone over sap. I haven't implemented this, however I'm also not sure how much sense this makes given the additional complexity for practically no gain (or I miss something). Comments welcome... Cheers Nico