rename ltlcheck as ltlcross

* src/bin/ltlcheck.cc, src/bin/man/ltlcheck.x,
src/tgbatest/ltlcheck.test, src/tgbatest/ltlcheck2.test: Rename as ...
* src/bin/ltlcross.cc, src/bin/man/ltlcross.x,
src/tgbatest/ltlcross.test, src/tgbatest/ltlcross2.test: ... these.
* NEWS, src/bin/Makefile.am, src/bin/man/Makefile.am,
src/tgbatest/Makefile.am: Adjust.

src/tgbatest/Makefile.am

@@ -107,9 +107,9 @@ TESTS = \
   emptchkr.test \
   ltlcounter.test \
   spotlbtt.test \
-  ltlcheck.test \
+  ltlcross.test \
   spotlbtt2.test \
-  ltlcheck2.test \
+  ltlcross2.test \
   complementation.test \
   randpsl.test \
   cycles.test