Returns the separator of directory according to the current platform ('\' or '/'). This allows you to build file paths without having to worry about the runtime platform (Windows or Linux for example).
// Returns the full name of the file by using the separator corresponding to the current platform
sFullName = sMyDirectory + [fSep()] + "file.txt"
// In Windows: sMyDirectory + "\file.txt"
// In Linux: sMyDirectory + "/file.txt"
<Result>: Character string
Separator used for the current platform: '\' or '/'.