nautilus-file-operations.c: Remove tailing dot and space for fat filesystems.
Nautilus is unable to copy or cut files ending with a dot or a space character on a FAT based filesystem. This will thow and error message.
The error message thrown will block the copy or cut operations.
To fix this a new function was created to replace tailing dot or space characters with the underscore character. Currectly, we are using the unserscore character to replace other forbidden characters.