genltl: reimplement using argp, and allowing ranges.

* src/bin/genltl.cc: New file.
* src/bin/Makefile.am: Add it.

src/bin/Makefile.am

@@ -24,5 +24,6 @@ AM_CPPFLAGS = -I$(top_srcdir)/src $(BUDDY_CPPFLAGS) \
 AM_CXXFLAGS = $(WARNING_CXXFLAGS)
 LDADD = $(top_builddir)/src/libspot.la $(top_builddir)/lib/libgnu.a
 
-bin_PROGRAMS = ltlfilt
+bin_PROGRAMS = ltlfilt genltl
 ltlfilt_SOURCES = ltlfilt.cc
+genltl_SOURCES = genltl.cc