File name of currently running code
p = mfilename('fullpath')
c = mfilename('class')
mfilename returns a string
containing the file name of the file in which the function call occurs.
When called from within the file, it returns the name of that file.
This allows a script or function to determine its name.
p = mfilename('fullpath') returns
the full path and name of the file in which the call occurs, not including
the filename extension.
c = mfilename('class') in
a method, returns the class of the method, not including the leading
If called from a nonmethod, it yields the empty string.