client/signal: Revert "add signal 'snapshot', rename existing signal 'wakeup' to 'replication'"

This was merged to master prematurely as the job components are not decoupled well enough
for these signals to be useful yet.

This reverts commit 2c8c2cfa14.

closes #452

daemon/snapper/snapper.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/pkg/errors"
 
-	"github.com/zrepl/zrepl/daemon/job/dosnapshot"
 	"github.com/zrepl/zrepl/daemon/logging/trace"
 
 	"github.com/zrepl/zrepl/config"
@@ -211,10 +210,6 @@ func syncUp(a args, u updater) state {
 		return u(func(s *Snapper) {
 			s.state = Planning
 		}).sf()
-	case <-dosnapshot.Wait(a.ctx):
-		return u(func(s *Snapper) {
-			s.state = Planning
-		}).sf()
 	case <-a.ctx.Done():
 		return onMainCtxDone(a.ctx, u)
 	}
@@ -383,10 +378,6 @@ func wait(a args, u updater) state {
 		return u(func(snapper *Snapper) {
 			snapper.state = Planning
 		}).sf()
-	case <-dosnapshot.Wait(a.ctx):
-		return u(func(snapper *Snapper) {
-			snapper.state = Planning
-		}).sf()
 	case <-a.ctx.Done():
 		return onMainCtxDone(a.ctx, u)
 	}

daemon/snapper/snapper_all.go

@@ -18,9 +18,9 @@ type PeriodicOrManual struct {
 	s *Snapper
 }
 
-func (s *PeriodicOrManual) Run(ctx context.Context, replicationCommon chan<- struct{}) {
+func (s *PeriodicOrManual) Run(ctx context.Context, wakeUpCommon chan<- struct{}) {
 	if s.s != nil {
-		s.s.Run(ctx, replicationCommon)
+		s.s.Run(ctx, wakeUpCommon)
 	}
 }