Issue: #96 - Garbage collect inodeproc once every 50 ui refresh as default.

- Reduce default frequency to avoid performance issue.
- The frequency of it can be modified with `-g` option
  and can be disabled with `-g 0`.

src/inode2prog.cpp

@@ -235,7 +235,8 @@ static quad_t get_ms() {
 static void get_pids(std::set<pid_t> *pids) {
   DIR *proc = opendir("/proc");
   if (proc == 0) {
-    std::cerr << "Error reading /proc, needed to get inode-to-pid-mapping" << std::endl;
+    std::cerr << "Error reading /proc, needed to get inode-to-pid-mapping"
+              << std::endl;
     exit(1);
   }
   dirent *entry;