Fix and improve nuxeoctl pending actions error management

When the pending actions (installAfterRestart.log) contains errors, then:

• a bug makes nuxeoctl currently report all actions next to the first error as error:
  wrong

  Error processing pending package/command: #nuxeo-multi-tenant #NXP-18016
  Error processing pending package/command: nuxeo-platform-importer
  Error processing pending package/command: nuxeo-platform-user-registration
  Error processing pending package/command: #nuxeo-quota
  Error processing pending package/command: nuxeo-signature
  Error processing pending package/command: #nuxeo-sites-blogs #optional
  Error processing pending package/command: nuxeo-spreadsheet
  Error processing pending package/command: nuxeo-template-rendering
  Error processing pending package/command: nuxeo-virtualnavigation
  Error processing pending package/command: nuxeo-web-mobile
  Error processing pending package/command: platform-explorer
  Error processing pending package/command: #resources-compat
  Error processing pending package/command: #nuxeo-sample
  Error processing pending package/command: #nuxeo-scan-importer
  Error processing pending package/command: shibboleth-authentication
  Error processing pending package/command: nuxeo-showcase-content
  Error processing pending package/command: microsoft-azure-online-storage
  Error processing pending package/command: nuxeo-travel-expenses
  Error processing pending package/command: nuxeo-salesforce
  Error processing pending package/command: nuxeo-review-workflows-dashboards
  

  right

  Error processing pending package/command: #nuxeo-multi-tenant #NXP-18016
  Error processing pending package/command: #nuxeo-sites-blogs #optional
  

• the parsing fails on commented lines containing spaces like #nuxeo-multi-tenant #NXP-18016
• the backup file should not contain the successful actions.