Golis's Sahal support

Support for Golis's Sahal mobile money system in Somalia has been added.
Take note that as usual all amounts are listed in the lowest currency denomications
As Sahal uses fractions of cents (aka uses 3 decimals) you have to divide the amounts by 1000 to get a "normal" representation.

Sahal support has been marked as experimental, until we have a confirmed real life test by someone "on the ground".
Thanks goes out to Saiid Cali for providing information about the system.