Cleaned up warnings and adjusted CFLAGS

This commit cleans up warnings and adjusts CFLAGS.  Thanks to
samuel.thibault@ens-lyon.org.

Makefile

@@ -1,5 +1,7 @@
 INSTALL = install
 
+CFLAGS = -Wall
+
 SRCS = \
 	cli.c \
 	espeakup.c  \

queue.c

@@ -136,6 +136,8 @@ void queue_process_entry(struct synth_t *s)
 		s->len = last->len;
 		error = speak_text(s);
 		break;
+	default:
+		break;
 	}
 	if (error == EE_OK)
 		queue_remove();

softsynth.c

@@ -21,7 +21,9 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
+#include <ctype.h>
 
 #include "espeakup.h"