FullFileNameList:
PROC
[shortName: ROPE, createTime: BasicTime.GMT ← BasicTime.nullGMT]
RETURNS[fullName: LIST OF ROPE];
Finds the list of all the full path names of a symbol or source file.
Assumes that shortName has an appropriate extension.
Returns the list containing shortName if it begins with [, / or <.
First tries FS.FileInfo on shortName, then prepends each element of pathPrefixes and uses FS.FileInfo to find the list of files.
Returns NIL if no files are found