include version.h in repo

Many code checking editors, marking the common.h as erroneous, as
version.h is missing. This can lead to confusion.
Change in Makefile.in with fake empty dependency ensures, that version.h
is recreated at every "make"
Another change in make clean, makes sure, that at this point a stub
version.h is generated.

version.h removed from .gitignore

.gitignore

@@ -10,7 +10,6 @@ sslh-ev
 systemd-sslh-generator
 sslh.8.gz
 tags
-version.h
 /config.status
 /config.log
 /config.h

Makefile.in

@@ -88,8 +88,9 @@ all: sslh-fork sslh-select $(MAN) echosrv $(CONDITIONAL_TARGETS)
 $(OBJS_A): $(OBJS)
  $(AR) rcs $(OBJS_A) $(OBJS)
 
-version.h:
+version.h: .FORCE
  ./genver.sh >version.h
+.FORCE: 
 
 $(OBJS) $(FORK_OBJS) $(SELECT_OBJS) $(EV_OBJS): argtable3.h collection.h common.h gap.h hash.h log.h probe.h processes.h sslh-conf.h tcp-listener.h tcp-probe.h tls.h udp-listener.h version.h
 
@@ -162,6 +163,7 @@ distclean: clean
 
 clean:
  rm -f sslh-fork sslh-select $(CONDITIONAL_TARGETS) echosrv version.h $(MAN) systemd-sslh-generator *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info
+ echo "// this is a placeholder for version.h, to make code-checking editors happy" > version.h
 
 tags:
  ctags --globals -T *.[ch]

version.h

@@ -0,0 +1 @@
+// this is a placeholder for version.h, to make code-checking editors happy