Fixed Issue #60. Improved randomization granularity for shuffleBed.

Previously used time() which has 1 second precision.
Now use gettimeofday() which has millisecond precision.

src/shuffleBed/shuffleBed.cpp

@@ -31,7 +31,11 @@ BedShuffle::BedShuffle(string &bedFile, string &genomeFile, string &excludeFile,
         srand(seed);
     }
     else {
-        srand((unsigned)time(0));
+        timeval tim;
+        gettimeofday(&tim, NULL);
+        int t1=tim.tv_sec+tim.tv_usec;
+        
+        srand((unsigned)t1);
     }
 
     _bed         = new BedFile(bedFile);

src/shuffleBed/shuffleBed.h

@@ -18,6 +18,7 @@
 #include <map>
 #include <cstdlib>
 #include <ctime>
+#include <sys/time.h>
 
 using namespace std;