This subroutine reads a file in to an array variable.
FileName - The file you are trying to retrieve, including the full path.
These are actual examples from the Aneuch source code:
@preview = FileToArray("$TempDir/$Page.$UserName");
In this example, which comes from the DoEdit sub, after the presence of a preview file was detected, we're going to read that preview file in to the array @preview. We want it in array format, as there is metadata at the top of the file, and the content at the bottom. It's easier to deal with it in array format.