Build It PureScript

bips wraps Pulp and simply forwards all arguments to Pulp, after running make -f prepare.make all in all dependant and dependency roots that have a prepare.make file. The makefiles must generate PureScript sources in the gen directory relative to prepare.make. bips passes all these gen directories to Pulp with the Pulp -I command-line option. Additionally make -f prepare.make clean can be run by invoking bips clean.