[FWI] Patch

I've commited to cvs some fixes to my last patch and additionally:

pid argument to http url, to set the PID field and enable sending SIM Toolkit messages
....&pid=127&coding=2&alt-dcs=1&mclass=3.  Now have fun creating your text and udh
fields :P (implemented in emi2 and at2)

alt-dcs argument to http url, to switch to the alternate coding of DCS, thus fixing the
"flash message to old mobiles (ericsson 688?)" problem (implemented in at2 and emi2)

added my-number configuration to at2 smsc group, enabling this number in logs instead
of the "1234"

added a keepalive to at2, sending an AT to the modem and reconnecting to it if it fails
(we could use this to check if the modem still have GSM network, I don't know how now)