doc: go1.7.txt updates

Change-Id: I6ac3d11ee8896f636235fe10c2556f93584019b5
Reviewed-on: https://go-review.googlesource.com/19984Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

doc/go1.7.txt

@@ -3,11 +3,18 @@ Tools:
 cmd/dist: add list subcommand to list all supported platforms (CL 19837)
 cmd/go: GO15VENDOREXPERIMENT gone, assumed on (CL 19615)
 cmd/link: "-X name value" form gone (CL 19614)
+cmd/compile: smaller binaries (many CLs)
+cmd/go, go/build: add support for Fortran (CL 19670, CL 4114)
+cmd/dist: introduce list subcommand to list all supported platforms (CL 19837)
 
 Ports:
 
-SOMETHING WILL HAPPEN
+We now require OpenBSD 5.6+ (CL 18219, crypto/rand using getentropy)
+plan9/arm support? Start at least.
 
 API additions and behavior changes:
 
 runtime: add CallerFrames and Frames (CL 19869)
+testing/quick: now generates nil values (CL 16470)
+net/url: support query string without values (CL 19931)
+net/textproto: permit all valid token chars in CanonicalMIMEHeaderKey input (CL 18725)