bufio: drop error return for NewReaderSize and NewWriterSize
It complicates the interface unnecessarily.
Document this in go1.html.
Also update the go/doc Makefile.
Fixes #2836.
R=golang-dev, gri, bradfitz
CC=golang-dev
https://golang.org/cl/5642054
diff --git a/doc/go1.html b/doc/go1.html
index ae91caa..95953dc 100644
--- a/doc/go1.html
+++ b/doc/go1.html
@@ -863,6 +863,22 @@
This category includes packages that are new in Go 1.
</p>
+<h3 id="bufio">The bufio package</h3>
+
+<p>
+In Go 1, <a href="/pkg/bufio/#NewReaderSize"><code>bufio.NewReaderSize</code></a>
+and
+<a href="/pkg/bufio/#NewWriterSize"><code>bufio.NewWriterSize</code></a>
+functions no longer return an error for invalid sizes.
+If the argument size is too small or invalid, it is adjusted.
+</p>
+
+<p>
+<em>Updating</em>:
+These functions are rarely used, and code must be updated by hand.
+All that is required is to drop the second return value.
+</p>
+
<h3 id="crypto_elliptic">The crypto/elliptic package</h3>
<p>
