add image counter, infty mode, make some faster

cmdlnopts.h

@@ -71,6 +71,7 @@ typedef struct{
     int showimage;      // show image preview
     int shmkey;         // shared memory (with image data) key
     int forceimsock;    // force using image through socket transition even if can use SHM
+    int infty;          // run (==1) or stop (==0) infinity loop
     float gain;         // gain level (only for CMOS)
     float brightness;   // brightness (only for CMOS)
     double exptime;     // time of exposition in seconds