Misc cleanups for job errors

vars/installVoltctl.groovy
--------------------------
  o npm-groovy-lint inspired cleanups.
  o Escape dollar on $var refs within sh() else jenkins thinks they are groovy.
  o Added functions enter() and leave() to normalize messages for logging.
  o Added attribute label for shell commands to make calls self-documenting.

jjb/voltha-e2e/voltha-2.8.yaml
------------------------------
  o Cosmetic edit to force pipeline job generation.

Change-Id: I6596ffb41af3c6f7891cbf2546db1cccb0c0ae2c
diff --git a/jjb/voltha-e2e/voltha-2.8.yaml b/jjb/voltha-e2e/voltha-2.8.yaml
index 67c4bda..4713a1a 100644
--- a/jjb/voltha-e2e/voltha-2.8.yaml
+++ b/jjb/voltha-e2e/voltha-2.8.yaml
@@ -30,7 +30,7 @@
           code-branch: 'voltha-2.8'
           extraHelmFlags: '--set kafka.externalAccess.enabled=true,kafka.externalAccess.service.type=NodePort,kafka.externalAccess.service.nodePorts[0]=30201,kafka.externalAccess.service.domain=127.0.0.1'
           time-trigger: "H H/23 * * *"
-          logLevel: 'INFO'
+          logLevel: 'DEBUG'
           testTargets: |
             - target: voltha-pm-data-single-kind-att
               workflow: att