Allow setting of bash completion path (todotxt#301)

Fixes todotxt#242

Makefile

@@ -30,7 +30,7 @@ endif
 ifdef BASH_COMPLETION
 	datarootdir = $(BASH_COMPLETION)
 else
-	datarootdir = $(prefix)/share
+	datarootdir = $(prefix)/share/bash_completion.d
 endif
 
 # Dynamically detect/generate version file as necessary
@@ -64,22 +64,22 @@ clean: test-pre-clean
 
 install: installdirs
 	$(INSTALL_PROGRAM) todo.sh $(DESTDIR)$(bindir)/todo.sh
-	$(INSTALL_DATA) todo_completion $(DESTDIR)$(datarootdir)/bash_completion.d/todo
+	$(INSTALL_DATA) todo_completion $(DESTDIR)$(datarootdir)/todo
 	[ -e $(DESTDIR)$(sysconfdir)/todo/config ] || \
 	    sed "s/^\(export[ \t]*TODO_DIR=\).*/\1~\/.todo/" todo.cfg > $(DESTDIR)$(sysconfdir)/todo/config
 
 uninstall:
 	rm -f $(DESTDIR)$(bindir)/todo.sh
-	rm -f $(DESTDIR)$(datarootdir)/bash_completion.d/todo
+	rm -f $(DESTDIR)$(datarootdir)/todo
 	rm -f $(DESTDIR)$(sysconfdir)/todo/config
 
-	rmdir $(DESTDIR)$(datarootdir)/bash_completion.d
+	rmdir $(DESTDIR)$(datarootdir)
 	rmdir $(DESTDIR)$(sysconfdir)/todo
 
 installdirs:
 	mkdir -p $(DESTDIR)$(bindir) \
 	         $(DESTDIR)$(sysconfdir)/todo \
-	         $(DESTDIR)$(datarootdir)/bash_completion.d
+	         $(DESTDIR)$(datarootdir)
 
 #
 # Testing
@@ -100,4 +100,5 @@ test: aggregate-results
 	rm -rf tests/test-results
 
 # Force tests to get run every time
-.PHONY: test test-pre-clean aggregate-results $(TESTS)
+.PHONY: test test-pre-clean aggregate-results $(TESTS)
+