*: reflow comments to 80 characters

This reformats the entire Metropolis codebase to have comments no longer
than 80 characters, implementing CR/66.

This has been done half manually, as we don't have a good integration
between commentwrap/Bazel, but that can be implemented if we decide to
go for this tool/limit.

Change-Id: If1fff0b093ef806f5dc00551c11506e8290379d0
diff --git a/metropolis/pkg/logtree/logtree_access.go b/metropolis/pkg/logtree/logtree_access.go
index fed202e..1babe1e 100644
--- a/metropolis/pkg/logtree/logtree_access.go
+++ b/metropolis/pkg/logtree/logtree_access.go
@@ -31,46 +31,54 @@
 	leveledWithMinimumSeverity Severity
 }
 
-// WithChildren makes Read return/stream data for both a given DN and all its children.
+// WithChildren makes Read return/stream data for both a given DN and all its
+// children.
 func WithChildren() LogReadOption { return LogReadOption{withChildren: true} }
 
-// WithStream makes Read return a stream of data. This works alongside WithBacklog to create a read-and-stream
-// construct.
+// WithStream makes Read return a stream of data. This works alongside WithBacklog
+// to create a read-and-stream construct.
 func WithStream() LogReadOption { return LogReadOption{withStream: true} }
 
-// WithBacklog makes Read return already recorded log entries, up to count elements.
+// WithBacklog makes Read return already recorded log entries, up to count
+// elements.
 func WithBacklog(count int) LogReadOption { return LogReadOption{withBacklog: count} }
 
-// BacklogAllAvailable makes WithBacklog return all backlogged log data that logtree possesses.
+// BacklogAllAvailable makes WithBacklog return all backlogged log data that
+// logtree possesses.
 const BacklogAllAvailable int = -1
 
 func OnlyRaw() LogReadOption { return LogReadOption{onlyRaw: true} }
 
 func OnlyLeveled() LogReadOption { return LogReadOption{onlyLeveled: true} }
 
-// LeveledWithMinimumSeverity makes Read return only log entries that are at least at a given Severity. If only leveled
-// entries are needed, OnlyLeveled must be used. This is a no-op when OnlyRaw is used.
+// LeveledWithMinimumSeverity makes Read return only log entries that are at least
+// at a given Severity. If only leveled entries are needed, OnlyLeveled must be
+// used. This is a no-op when OnlyRaw is used.
 func LeveledWithMinimumSeverity(s Severity) LogReadOption {
 	return LogReadOption{leveledWithMinimumSeverity: s}
 }
 
-// LogReader permits reading an already existing backlog of log entries and to stream further ones.
+// LogReader permits reading an already existing backlog of log entries and to
+// stream further ones.
 type LogReader struct {
-	// Backlog are the log entries already logged by LogTree. This will only be set if WithBacklog has been passed to
-	// Read.
+	// Backlog are the log entries already logged by LogTree. This will only be set if
+	// WithBacklog has been passed to Read.
 	Backlog []*LogEntry
-	// Stream is a channel of new entries as received live by LogTree. This will only be set if WithStream has been
-	// passed to Read. In this case, entries from this channel must be read as fast as possible by the consumer in order
-	// to prevent missing entries.
+	// Stream is a channel of new entries as received live by LogTree. This will only
+	// be set if WithStream has been passed to Read. In this case, entries from this
+	// channel must be read as fast as possible by the consumer in order to prevent
+	// missing entries.
 	Stream <-chan *LogEntry
-	// done is channel used to signal (by closing) that the log consumer is not interested in more Stream data.
+	// done is channel used to signal (by closing) that the log consumer is not
+	// interested in more Stream data.
 	done chan<- struct{}
-	// missed is an atomic integer pointer that tells the subscriber how many messages in Stream they missed. This
-	// pointer is nil if no streaming has been requested.
+	// missed is an atomic integer pointer that tells the subscriber how many messages
+	// in Stream they missed. This pointer is nil if no streaming has been requested.
 	missed *uint64
 }
 
-// Missed returns the amount of entries that were missed from Stream (as the channel was not drained fast enough).
+// Missed returns the amount of entries that were missed from Stream (as the
+// channel was not drained fast enough).
 func (l *LogReader) Missed() uint64 {
 	// No Stream.
 	if l.missed == nil {
@@ -79,8 +87,8 @@
 	return atomic.LoadUint64(l.missed)
 }
 
-// Close closes the LogReader's Stream. This must be called once the Reader does not wish to receive streaming messages
-// anymore.
+// Close closes the LogReader's Stream. This must be called once the Reader does
+// not wish to receive streaming messages anymore.
 func (l *LogReader) Close() {
 	if l.done != nil {
 		close(l.done)
@@ -91,9 +99,11 @@
 	ErrRawAndLeveled = errors.New("cannot return logs that are simultaneously OnlyRaw and OnlyLeveled")
 )
 
-// Read and/or stream entries from a LogTree. The returned LogReader is influenced by the LogReadOptions passed, which
-// influence whether the Read will return existing entries, a stream, or both. In addition the options also dictate
-// whether only entries for that particular DN are returned, or for all sub-DNs as well.
+// Read and/or stream entries from a LogTree. The returned LogReader is influenced
+// by the LogReadOptions passed, which influence whether the Read will return
+// existing entries, a stream, or both. In addition the options also dictate
+// whether only entries for that particular DN are returned, or for all sub-DNs as
+// well.
 func (l *LogTree) Read(dn DN, opts ...LogReadOption) (*LogReader, error) {
 	l.journal.mu.RLock()
 	defer l.journal.mu.RUnlock()