Added the argument 'schema' to make such that 'make schema' rebuilds fluidity_options.rng, updating with any changes to fluidity_options.rnc and its dependencies.
Added the argument 'schema' to make such that 'make schema' rebuilds fluidity_options.rng, updating with any changes to fluidity_options.rnc and its dependencies.


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