Checks if a file equals another.
The two files compared are equal if they have the same pathname.
The two files compared are not equal if:
other is not a
their file sizes differ, or
their file checksums differ.
If none of the above occurs, the two files are considered equal.
Note that subclasses use refined rules.
TRUE if the file equals the other, otherwise
FALSE, attributes are added specifying the pathnames of the two
files compared, and the reason for them being different.