* build fixes

src/StretcherProcess.cpp

@@ -690,7 +690,7 @@ RubberBandStretcher::Impl::modifyChunk(size_t channel,
     if (limit2 < limit1) limit2 = limit1;
     
     double prevInstability = 0.0;
-    double prevDirection = 0.0;
+    bool prevDirection = false;
 
     double distance = 0.0;
     const double maxdist = 8.0;

src/main.cpp

@@ -41,7 +41,7 @@ using RubberBand::usleep;
 
 double tempo_convert(const char *str)
 {
-    char *d = strchr(str, ':');
+    char *d = strchr((char *)str, ':');
 
     if (!d || !*d) {
         double m = atof(str);