Bugfix: Miscellaneous problems in file functons and Featureless Make related code.

Bugfix: Miscellaneous problems in file functons and Featureless Make related code.

Fix documentation inaccuracies such as "Set to 0 to not use." when 0 is not a "not use" value and is instead a valid value with discrete meaning.
Remove documentation about non-existent parameter "file".
Clarify the wording in some of the documentation.

Add missing return on error check after several memory allocation function calls.

Add missing range parameter checks.

Error checking is being performed on wrong status variable and wrong status variable is being returned.

Perform some general code clean up as encountered.