Allow Stdin input on CLI commands

[tinova]

Description

Currently templates for resouces cannot be input as stdin, only files allowed

To Reproduce

Try to create a resource in OpenNebula with the CLI on a bash pipe

Expected behavior

Allow Stdin in the CLI, instead of awkward workarounds like temp files.

Details

• Affected Component: CLI
• Hypervisor: All
• Version: development

Progress Status

• Code committed
  • onevm create
  • onevm disk-attach
  • onevm nic-attach
  • onevm resize
  • onevm updateconf
  • onedatastore create
  • oneimage create
  • onemarket create
  • onemarketapp create
  • onetemplate create
  • onetemplate instantiate
  • onevnet create
  • onevrouter create
  • onevrouter instantiate
  • onevrouter nic-attach
  • oneflow-template create
  • oneflow-template instantiate
• Testing - QA
  • onevm create
  • onevm disk-attach
  • onevm nic-attach
  • onevm resize
  • onevm updateconf
  • onedatastore create
  • oneimage create
  • onemarket create
  • onemarketapp create
  • onetemplate create
  • onetemplate instantiate
  • onevnet create
  • onevrouter create
  • onevrouter instantiate
  • onevrouter nic-attach
  • oneflow-template create
  • oneflow-template instantiate
• Documentation
  • Release notes
  • compatibility
  • bash symbols escaping

[paczerny]

stdin for update methods not implement, the method is used for almost all commands. The processing of all commands is here
Add

elsif STDIN.wait_readable(0)
    STDIN.read

in front of elseif append should fix it.