core/kmeraffect.{h,cpp}: KmerAffect copy constructor, with reverse

algo/core/kmeraffect.cpp

@@ -79,6 +79,12 @@ KmerAffect::KmerAffect(const KmerAffect &ka) {
   affect = ka.affect;
 }
 
+KmerAffect::KmerAffect(const KmerAffect &ka, bool reverse) {
+  affect = ka.affect;
+  if (reverse)
+    affect.c ^= (1 << 7);
+}
+
 KmerAffect::KmerAffect(const string &label,
                        int strand) {
   affect.c = label[0];

algo/core/kmeraffect.h

@@ -65,6 +65,11 @@ public:
    */ 
   KmerAffect(const KmerAffect &ka);
 
+  /*
+   * Copy constructor, possibly reversing the strand if 'reverse' is true
+   */
+  KmerAffect(const KmerAffect &ka, bool reverse);
+     
   /**
    * Construct an affectation as stated by the parameters
    * @post affect_strand(affect) == strand AND affect_char(affect) == kmer[0]