Remove duplicate function. FileStateToChar is defined and used in files_lib.c
Kill global VINPUTFILE, with fire

Leaving global MINUSF intact for now, may need to be wrapped up in some
context object.
Merge pull request #298 from sigurdteigen/cleanup/remove-vinputfile

Kill global VINPUTFILE, with fire
add canonify() to some handle promises to prevent cf-promises FATAL error about invalid rvalue