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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: "#]"
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

version_added: '2.6'
  force:
    description:
    - Determine when the file is being transferred if the destination already exists.
    - When set to C(yes), replace the remote file when contents are different than the source.
    - When set to C(no), the file will only be transferred if the destination does not exist.
    type: bool
    default: yes
  output_encoding:
    description:
    - Overrides the encoding used to write the template file defined by C(dest).
    - It defaults to C(utf-8), but any encoding supported by python can be used.
    - The source template file must always be encoded using C(utf-8), for homogeneity.
    type: str
    default: utf-8
    version_added: '2.7'
notes:
- Including a string that uses a date in the template will result in the template being marked 'changed' each time.
- Since Ansible 0.9, templates are loaded with C(trim_blocks=True).
- >
  Also, you can override jinja2 settings by adding a special header to template file.
  i.e. C(#jinja2:variable_start_string:'[%', variable_end_string:'%]', trim_blocks: False)
  which changes the variable interpolation markers to C([% var %]) instead of C({{ var }}).
  This is the best way to prevent evaluation of things that look like, but should not be Jinja2.
- Using raw/endraw in Jinja2 will not work as you expect because templates in Ansible are recursively
  evaluated.
- To find Byte Order Marks in files, use C(Format-Hex <file> -Count 16) on Windows, and use C(od -a -t x1 -N 16 <file>)
  on Linux.
'''