Config template V2 from Grandstream. first model with new style of XML template. Does not use "P" codes.
MPK settings are not programmed in this commit.
* Add template for GAC2500
Initial gac2500 config template for firmware 1.0.3.30 or higher. all settings are either default or use variables from FusionPBX
* New GAC2500 template based on Firmware version 1.0.3.30 defaults
Only changes from defaults are FusionPBX variables and enable paging auto answer