Filename exclusion (with -i) works only for the source files.
Print a warning if user tries to exclude header file. The warning
instructs user to use --suppress for ignoring warnings from the
header files.
Initially I added logic that checked if excluded path was a file
we would accept. This works for source files, but when file with
"unknown" extension was given it was determined as a directory
name and ending slash was added. E.g. -ifile.h would end up
having ignored path file.h/.
This commit adds per-platform checks if the path points to the
file and if the file also exists.
Daniel Marjamäki
Kimmo Varis
Greg Hewgill
Robert Reif
Kimmo Varis