Fix for incorrect return value in Genotype.getAnyAttribute()

* The Genotype.getAnyAttribute() incorrectly handles converting int[] to
  List<Integer>.  Both getAD() and getPL() return an int[], and doing
  Arrays.asList(int[]) will return a List<int[]> instead of List<Integer>.

See: #274

src/java/htsjdk/variant/variantcontext/Genotype.java

@@ -541,9 +541,19 @@ public Object getAnyAttribute(final String key) {
  } else if (key.equals(VCFConstants.GENOTYPE_QUALITY_KEY)) {
  return getGQ();
  } else if (key.equals(VCFConstants.GENOTYPE_ALLELE_DEPTHS)) {
- return Arrays.asList(getAD());
+ if (hasAD()) {
+ final List<Integer> intList = new ArrayList<Integer>(getAD().length);
+ for(int i : getAD()) intList.add(i);
+ return intList;
+ }
+ return Collections.EMPTY_LIST;
  } else if (key.equals(VCFConstants.GENOTYPE_PL_KEY)) {
- return Arrays.asList(getPL());
+ if (hasPL()) {
+ final List<Integer> intList = new ArrayList<Integer>(getPL().length);
+ for(int i : getPL()) intList.add(i);
+ return intList;
+ }
+ return Collections.EMPTY_LIST;
  } else if (key.equals(VCFConstants.DEPTH_KEY)) {
  return getDP();
  } else {