Handles can now be passed into subroutines and functions

Now Liberty BASIC code can pass a handle to a window, control, file, etc. into subroutines and functions.  This makes it possible to make your code more flexible and reusable.

    'file example
    'Open a file for displaying
    fName$ = "fileA.txt"
    open fName$ for input as #firstFile
    call displayFile fName$, #firstFile
    close #firstFile
    'Open another file for displaying
    fName$ = "fileB.txt"
    open fName$ for input as #secondFile
    call displayFile fName$, #secondFile
    close #secondFile
    print
    print "Done."
    end

sub displayFile displayName$, #fHandle
    print "Displaying the contents of "; displayName$
    print "==============================================="
    while eof(#fHandle) = 0
        line input #fHandle, fileText$
        print fileText$
    wend
    print "==============================================="
    print
end sub