Merge pull request #2 from razhangwei/patch-1

Fix the ambiguous issue when compiled on linux.

Hawkes.cpp

@@ -334,7 +334,7 @@ void updateBaseline (dataPackage *info) {
  integral += tmp * wholeDuration[p][ii];
  }
 
- if (isinf(integral) || isnan(integral)) {
+ if (std::isinf(integral) || std::isnan(integral)) {
  cerr << "Invalid integral value. Need to shrink step size for FISTA." << endl;
  exit(1);
  }