sms-service timestamp

Hi,

There was an issue raised by E. Chanson and confirmed by A Cornejo regarding 
sms-service. The timestamp parameter, %t, always prints GMT time, by calling 
gw_gmttime in gw/ultrans.c, obey_request(). It took several mails and 
explanations to understand what was going on. Basically both users would 
like timestamp with localtime.

The logic behingd gw_gmttime is solid. Since outgoing HTTP requests can be 
anywhere in the world, and timezones are not known ahead of time, send GMT 
time and let receiving applications handle it. Some action is needed to not 
have similar questions in the future.

1) Add a localtime boolean variable in sms-service configuration with 
default value false (GMT) and update documentation accordingly.
2) Update documentation as to for the reasons that GMT time is used and let 
users know that they should adjust it in their receiving app.

(1) Has the danger of inflating sms-service with a zillion configuration 
variables (it will be only 1 actually, but you get the meaning)
(2) You have no control over applications running half-way across the world, 
just the ones that you control, and they probably need localtime. 
Applications that are not controlled by you, probably don't need a 
timestamp, or that timestamp is useless to you, eitherway. This probably 
argues that timestamp in sms-service should be localtime, since it is only 
useful to users' aplications.

I could provide a patch for either, just let me know, which would be 
preferable.

BR,
Nikos