Initial import. Most things seem working.

This includes an abortive attempt to do a gtk4 dialog (which I don't
think is possible, as gtk4 doesn't allow embedding toplevels anymore),
and an iced dialog, which I just never started writing.

Makefile

@@ -0,0 +1,47 @@
+.PHONY: all build build-dev install clean uninstall run
+
+PREFIX ?= /usr/local
+BINDIR ?= $(PREFIX)/bin
+LIBEXECDIR ?= $(PREFIX)/libexec
+
+HELPER_DIR = $(LIBEXECDIR)/bscreensaver
+HELPERS = \
+	bscreensaver-dbus-service \
+	bscreensaver-systemd \
+	bscreensaver-dialog-gtk3 \
+	$(NULL)
+
+INSTALL ?= install
+
+DEV_LOG_LEVEL = debug
+
+all: build
+
+build:
+	HELPER_DIR=$(HELPER_DIR) cargo build --release
+
+build-dev:
+	HELPER_DIR=target/debug cargo build
+
+install: build
+	$(INSTALL) -m 0755 -d $(BINDIR) $(HELPER_DIR)
+	$(INSTALL) -m 0755 target/release/bscreensaver $(BINDIR)
+	$(INSTALL) -m 0755 $(addprefix target/release/,$(HELPERS)) $(HELPER_DIR)
+
+clean:
+	cargo clean
+
+uninstall:
+	rm -f $(BINDIR)/bscreensaver $(addprefix $(HELPER_DIR)/,$(HELPERS)) || true
+	rmdir -p $(BINDIR) $(HELPER_DIR) || true
+	rmdir -p $(PREFIX) || true
+
+run: build-dev
+	BSCREENSAVER_LOCAL_DEV=1 \
+	RUST_BACKTRACE=1 \
+	BSCREENSAVER_LOG=$(DEV_LOG_LEVEL) \
+	BSCREENSAVER_DBUS_SERVICE_LOG=$(DEV_LOG_LEVEL) \
+	BSCREENSAVER_SYSTEMD_LOG=$(DEV_LOG_LEVEL) \
+	BSCREENSAVER_DIALOG_GTK3_LOG=$(DEV_LOG_LEVEL) \
+	HELPER_DIR=target/debug \
+	cargo run --bin bscreensaver