bees: add version string and put it in main() and stats file

Now that we have more than one bees release it's somewhat important
to know which one each bug report is for...

src/Makefile

@@ -11,6 +11,8 @@ LIBS = -lcrucible -lpthread
 LDFLAGS = -L../lib -Wl,-rpath=$(shell realpath ../lib)
 
 depends.mk: Makefile *.cc
+	echo "#define BEES_VERSION \"$(shell git describe --always --dirty || echo UNKNOWN)\"" > bees-version.new.h
+	mv -f bees-version.new.h bees-version.h
 	for x in *.cc; do $(CXX) $(CXXFLAGS) -M "$$x"; done > depends.mk.new
 	mv -fv depends.mk.new depends.mk
 
@@ -36,4 +38,4 @@ BEES_OBJS = \
 	$(CXX) $(CXXFLAGS) -o "$@" $(BEES_OBJS) $(LDFLAGS) $(LIBS)
 
 clean:
-	-rm -fv *.o
+	-rm -fv *.o bees-version.h