* src/bin/common_range.cc, src/bin/common_range.hh: New files,
extracted from...
* src/bin/genltl.cc: ... here.
* src/bin/randltl.cc, src/bin/man/randltl.x: New files.
* src/bin/Makefile.am, src/bin/man/Makefile.am: Adjust.
* src/bin/man/genltl.x: Point to randltl(1).