Remove the Makefile and the redundant install instructions

We can now install purely using cabal, no Makefile needed.
The install instrcutions previously said to install the data
file manually, but cabal does that for us now.

cabal-install/INSTALL

-After building and installing with cabal, copy etc-cabal-install to
-/etc/cabal-install.

cabal-install/Makefile

-
-HC=ghc
-GHCFLAGS=--make -package Cabal -Wall -fno-warn-unused-matches -cpp
-PREF=/usr/local
-
-all: setup build
-
-help:
-	@echo
-	@echo "For a user-install (~/bin/cabal-instal) do:"
-	@echo "  $$ make install-user"
-	@echo
-	@echo "For a sistem-wide install do:"
-	@echo "  $$ make"
-	@echo "  $$ sudo make install"
-	@echo
-
-setup:
-	mkdir -p dist/tmp
-	$(HC) $(GHCFLAGS) -odir dist/tmp -hidir dist/tmp Setup.lhs -o setup
-
-config: setup
-	./setup configure --ghc --prefix=$(PREF)
-
-build: config
-	./setup build
-
-.PHONY: install
-install:
-	./setup install
-	mkdir -p /etc/cabal-install
-	cp etc-cabal-install/serv.list /etc/cabal-install/
-
-config-user: setup
-	./setup configure --ghc --prefix=${HOME}
-
-build-user: config-user
-	./setup build
-
-.PHONY: install-user
-install-user: build-user
-	./setup install
-	mkdir -p ${HOME}/.cabal-install
-	cp etc-cabal-install/serv.list ${HOME}/.cabal-install/
-
-clean:
-	rm -rf *.o *.hi setup cabal-install dist/
-