Increase wait for +HTTPACTION: to 8000ms because a server may be slow
Split doGTTPGET in three parts so that you can do multiple GETs

The old doHTTPGET does the same thing, but now there are three lower
level functions:
 * doHTTPGET1 - setup the connection to the GPRS network
 * doHTTPGET2 - just do the GET with an URL
 * doHTTPGET3 - close the connection
Wait 500 ms after switching off and "NORMAL POWER DOWN"

After this delay a much more reliable reading of the CTS pin is possible.
The 500ms is just a wild guess. Feel free to try shorter delays.

This update also changes first delay before the "power" toggle. The pin
should already be in a LOW state when we start toggle().