add_sourcefile

Mark a range of address as belonging to a source file
   An address range may belong only to one source file.
   A source file may be represented by several address ranges.
        ea1     - linear address of start of the address range
        ea2     - linear address of end of the address range
        filename- name of source file.
   returns: 1-ok, 0-failed.

success add_sourcefile(long ea1, ulong ea2, string filename);