Existing Wording: build tools

Comment:

Currently, the FHIR base resource spreadsheet must declare all profiles. It would be preferable to have the profiled resource declare the external base resource that it extends. This small change would eliminate the need to edit the base resource spreadsheet in order to add a profile to the FHIR build. More importantly, having references point from profiles to base resources, rather than the reverse, would enable the core to be separated from the myriad profiles built on the core. It would lead to a more sustainable architecture, where the core was self-contained and inviolable. Correcting the direction of references is a necessary step to begin to modularize the build system, eventually to allow users to build their profiles locally, more quickly, and without recompiling the core.