Fix some sign-compare warnings

src/bme/bme_main.h

@@ -184,7 +184,7 @@ typedef struct
 
 typedef struct
 {
-  unsigned rawcode;
+  int rawcode;
   char *name;
 } KEY;
 

src/bme/bme_snd.c

@@ -161,7 +161,7 @@ void noteOff(unsigned char note) {
 }
 
 void snd_midi_process(double timeStamp, const unsigned char *message, size_t messageSize, void *userData) {
-    int i;
+    size_t i;
 
     for (i = 0; i < messageSize; i++) {
          //printf("size: %u: %02X %u %u\n", messageSize,

src/gdisplay.c

@@ -20,7 +20,7 @@ char timechar[] = {':', ' '};
 
 int timemin = 0;
 int timesec = 0;
-int timeframe = 0;
+unsigned timeframe = 0;
 
 void initcolorscheme(int dark)
 {

src/gplay.h

@@ -15,7 +15,7 @@ typedef struct
   unsigned char note;
   unsigned char lastnote;
   unsigned char newnote;
-  unsigned pattptr;
+  int pattptr;
   unsigned char pattnum;
   unsigned char songptr;
   unsigned char repeat;