Add %g support to mg_snprintf()

src/str.h

@@ -31,15 +31,18 @@ bool mg_match(struct mg_str str, struct mg_str pattern, struct mg_str *caps);
 bool mg_globmatch(const char *pattern, size_t plen, const char *s, size_t n);
 bool mg_commalist(struct mg_str *s, struct mg_str *k, struct mg_str *v);
 bool mg_split(struct mg_str *s, struct mg_str *k, struct mg_str *v, char delim);
-size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list ap);
+size_t mg_vsnprintf(char *buf, size_t len, const char *fmt, va_list *ap);
 size_t mg_snprintf(char *, size_t, const char *fmt, ...);
 char *mg_hex(const void *buf, size_t len, char *dst);
 void mg_unhex(const char *buf, size_t len, unsigned char *to);
 unsigned long mg_unhexn(const char *s, size_t len);
 size_t mg_asprintf(char **, size_t, const char *fmt, ...);
 size_t mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap);
+char *mg_mprintf(const char *fmt, ...);
+char *mg_vmprintf(const char *fmt, va_list ap);
 int mg_check_ip_acl(struct mg_str acl, uint32_t remote_ip);
 int64_t mg_to64(struct mg_str str);
 uint64_t mg_tou64(struct mg_str str);
 size_t mg_lld(char *buf, int64_t val, bool is_signed, bool is_hex);
 double mg_atod(const char *buf, int len, int *numlen);
+size_t mg_dtoa(char *buf, size_t len, double d, int width);