Update API info, remove VNUMpfx prototype.

include/vnum.h

@@ -32,7 +32,6 @@
 
 /* from libvarnish/vnum.c */
 double VNUM(const char *p);
-double VNUMpfx(const char *p, const char **e);
 vtim_dur VNUM_duration_unit(vtim_dur r, const char *b, const char *e);
 vtim_dur VNUM_duration(const char *p);
 int64_t VNUM_bytes_unit(double r, const char *b, const char *e, uintmax_t rel,

include/vrt.h

@@ -54,6 +54,7 @@
  * binary/load-time compatible, increment MAJOR version
  *
  * NEXT (2021-09-15)
+ *	VNUMpfx() removed, SF_Parse_{Integer|Decimal|Number} added
  *	vrt_null_strands added
  *	vrt_null_blob added
  *	VRT_NULL_BLOB_TYPE added as the .type of vrt_null_blob