* src/misc/formater.cc, src/misc/formater.hh (scan): New method.
(prime): Use it.
* src/bin/ltlcross.cc (translator_runner::translator_runner): Scan each
specification string, and report those missing an input or output
%-sequence.
* NEWS: Mention it.
* src/misc/formater.hh (formater::format, formater::prime): Move ...
* src/misc/formater.cc: ... in this new file.
* src/misc/Makefile.am: Add it.
* src/sanity/style.test: Allow <iostream> in headers where << or >> are
used.