Add visibility pragma to hiload library header.

Add hiload to minimal

test/manual/minimal.cpp

@@ -1,11 +1,16 @@
 #include "minimal_lib.h"
 
+// We're not installing anything, so this is a bit weird here
+#include "../../include/hiload/hiload.h"
+
 #include <chrono>
 #include <cstdio>
 #include <thread>
 
 int main(int argc, char *argv[]) {
 
+  hi_init();
+
   int modified = -1;
   while (modified != 0) {
 
@@ -25,5 +30,7 @@ int main(int argc, char *argv[]) {
     printf("\n");
   }
 
+  hi_deinit();
+
   return 0;
 }