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##### SUMMARY
Add comment_start_string and comment_end_string to template plugin.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
template

##### ADDITIONAL INFORMATION
In some situation, we need to change comment behavior of template plugin, for an example macros in Zabbix is like {#MACRO}.

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: Render a template with "comment_start_string" set to [#
  template:
    src: template.xml.j2
    dest: template.xml
    comment_start_string: "[#"
    comment_end_string: "#]"
```

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- C(template_run_date) is the date that the template was rendered.
options:
  src:
    description:
    - Path of a Jinja2 formatted template on the Ansible controller.
    - This can be a relative or an absolute path.
    - The file must be encoded with C(utf-8) but I(output_encoding) can be used to control the encoding of the output
      template.
    type: path
    required: yes
  dest:
    description:
    - Location to render the template to on the remote machine.
    type: path
    required: yes
  newline_sequence:
    description:
    - Specify the newline sequence to use for templating files.
    type: str
    choices: [ '\n', '\r', '\r\n' ]
    default: '\n'
    version_added: '2.4'
  block_start_string:
    description:
    - The string marking the beginning of a block.
    type: str
    default: '{%'
    version_added: '2.4'
  block_end_string:
    description: