test: Add a check for too long or badly reflowed docstrings

This ensures that docstring comments are wrapped to 80 chars. ffrank
seemed to be making this mistake far too often, and it's a silly thing
to look for manually. As it turns out, I've made it too, as have many
others. Now we have a test that checks for most cases. There are still a
few stray cases that aren't checked automatically, but this can be
improved upon if someone is motivated to do so.

Before anyone complains about the 80 character limit: this only checks
docstring comments, not source code length or inline source code
comments. There's no excuse for having docstrings that are badly
reflowed or over 80 chars, particularly if you have an automated test.

util/socketset/socketset.go

@@ -35,8 +35,8 @@ import (
 )
 
 // SocketSet is used to receive events from a socket and shut it down cleanly
-// when asked. It contains a socket for events and a pipe socket to unblock receive
-// on shutdown.
+// when asked. It contains a socket for events and a pipe socket to unblock
+// receive on shutdown.
 type SocketSet struct {
 	fdEvents int
 	fdPipe   int
@@ -80,8 +80,8 @@ func NewSocketSet(groups uint32, name string, proto int) (*SocketSet, error) {
 }
 
 // ReceiveBytes waits for bytes from fdEvents and return a byte array truncated
-// to the message length. It will block until an event is produced, or shutdown is
-// called.
+// to the message length. It will block until an event is produced, or shutdown
+// is called.
 func (obj *SocketSet) ReceiveBytes() ([]byte, error) {
 	// Select will return when any fd in fdSet (fdEvents and fdPipe) is ready
 	// to read.