Removed insertion point to prevent unexpected substitution of a jump placeholder.

This change is based on Case 261334 with Bare Bones technical support regarding the "<##>" strings being inserted at then end of certain Clippings. Thanks to Patrick Woolsey for clarification.
Added a supported_architectures selection which allows quick removal of the PowerPC architecture.

When completing supported_architectures, the PowerPC architecture is selected. Press Delete to remove it. The i386 and x86_64 architectures will remain.