strings and bytes.Split: make count of 0 mean 0, not infinite.
Use a count of -1 for infinity.  Ditto for Replace.

R=rsc
CC=golang-dev
https://golang.org/cl/1704044
diff --git a/src/pkg/unicode/maketables.go b/src/pkg/unicode/maketables.go
index 75d1641..4fc41cd 100644
--- a/src/pkg/unicode/maketables.go
+++ b/src/pkg/unicode/maketables.go
@@ -236,7 +236,7 @@
 // Extract the version number from the URL
 func version() string {
 	// Break on slashes and look for the first numeric field
-	fields := strings.Split(*url, "/", 0)
+	fields := strings.Split(*url, "/", -1)
 	for _, f := range fields {
 		if len(f) > 0 && '0' <= f[0] && f[0] <= '9' {
 			return f
@@ -304,7 +304,7 @@
 		return
 	}
 	// Find out which categories to dump
-	list := strings.Split(*tablelist, ",", 0)
+	list := strings.Split(*tablelist, ",", -1)
 	if *tablelist == "all" {
 		list = allCategories()
 	}
@@ -580,7 +580,7 @@
 	resp.Body.Close()
 
 	// Find out which scripts to dump
-	list := strings.Split(flaglist, ",", 0)
+	list := strings.Split(flaglist, ",", -1)
 	if flaglist == "all" {
 		list = all(table)
 	}