added current acer_c720 next config
fixed problems with modunion program

Fixed several problems with modunion:

  - Ignored modules file given on command line.

  - chomp newline of read in previous modules.

  - Renamed @a to @as to avoid confusion with $a.
    Did the same with @b.

  - Exchanged order of array index check with
    pattern check to fix invalid comparisons.