unify configure command line saving between configure.sh and configure.exe

It's slightly confusing to have different names for this file on different systems. configure.cache has the disadvantage of having each configure parameter on a new line, which makes it hard to copy and paste them to the command line the next time you run configure; whereas config.status is a shell script (despite not being named like one). On Windows it could have an additional .bat or .cmd extension in order to be a script which can be run again to reconfigure, or it could at least have all the configure parameters on one line for convenience, and be named the same.