Revised GCCE workaround for Bug 2926 - must use :zip export to ensure that the various files are present before any builds are attempted, otherwise there is "no rule to make usrt3_1.lib" and no attempt is made to link any executables even after the extension makefiles are executed.

T_SERIAL	OK
T_SOUND		OK except for FreeLogicalDevice bits
T_ATADRV	OK
T_IDRV		OK
T_PCCD1		Not yet implemented
T_PCCD2		Not yet implemented
T_PCCD3		Not yet implemented
T_POWR		OK
T_HAL		OK
T_INF		OK
T_PTNOS		Not yet implemented
T_RESET
T_PS		OK
T_COLOUR	OK
T_WWINS		OK