Update README, version.

README

@@ -1,4 +1,4 @@
-MiniCARD 1.1, based on MiniSAT 2.2.0
+MiniCARD 1.2, based on MiniSAT 2.2.0
  Mark Liffiton and Jordyn Maglalang
  <[email protected]>,<[email protected]>
 
@@ -35,6 +35,13 @@ options.
 HISTORY
 -------
 
+Version 1.2 added duplicate-literal handline in cardinality constraints.  Each
+copy of a literal within a cardinality constraint will "count" separately
+toward the constraint's bound.  For example, AtMost({x1, x1, x2}, 2) will be
+violated if x1 and x2 are both True.  This allows for "instrumented" or
+"implied" cardinality constraints.  For example, AtMost({y, y, x1, x2, x3}, 3)
+is equivalent to y -> AtMost({x1, x2, x3}, 1).
+
 Version 1.1 added a basic ability to parse and solve OPB-format instances
 (http://www.cril.univ-artois.fr/PB12/format.pdf) in which the constraints are
 limited to linear cardinality constraints only (i.e., all weights are -1 or