A fix to ensure 'make schema' succeeds on a fresh checkout.
A fix to ensure 'make schema' succeeds on a fresh checkout.

This commit adds a Makefile directive to install spud-preprocess, which is required by the 'schema' directive.
Note that this new directive does not interfere with the build of libspud, which is performed within its own directory.
It is only called when required by 'make schema'.

rjferrier/fluidity,rjferrier/fluidity,jrper/fluidity,rjferrier/fluidity,iakovos-panourgias/fluidity,jjo31/ATHAM-Fluidity,jrper/fluidity,jjo31/ATHAM-Fluidity,iakovos-panourgias/fluidity,iakovos-panourgias/fluidity,rjferrier/fluidity,jjo31/ATHAM-Fluidity,rjferrier/fluidity,jjo31/ATHAM-Fluidity,jjo31/ATHAM-Fluidity,jrper/fluidity,jrper/fluidity,jrper/fluidity,iakovos-panourgias/fluidity,iakovos-panourgias/fluidity