docs: float->float64 plus a couple of other tweaks.

R=rsc, gri
CC=golang-dev
https://golang.org/cl/3978042
diff --git a/doc/install.html b/doc/install.html
index 92b099f..5917da9 100644
--- a/doc/install.html
+++ b/doc/install.html
@@ -45,11 +45,10 @@
 </dt>
 <dd>
 	Incomplete.
-	It only supports Linux binaries, the optimizer is not enabled,
-	and floating point is performed entirely in software.
+	It only supports Linux binaries, the optimizer is incomplete,
+	and floating point uses the VFP unit.
 	However, all tests pass.
-	Work on the optimizer and use of the VFP hardware
-	floating point unit is underway.
+	Work on the optimizer is continuing.
 	Tested against a Nexus One.
 </dd>
 </dl>