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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 -->

def run(self, terms, variables, **kwargs):
        ret = []
        self.set_options(var_options=variables, direct=kwargs)
        
        convert_data_p = self.get_option('convert_data')
        lookup_template_vars = self.get_option('template_vars')
        jinja2_native = self.get_option('jinja2_native')
        variable_start_string = self.get_option('variable_start_string')
        variable_end_string = self.get_option('variable_end_string')
        if USE_JINJA2_NATIVE and not jinja2_native:
            templar = self._templar.copy_with_new_env(environment_class=AnsibleEnvironment)
        else:
            templar = self._templar
        for term in terms:
            display.debug("File lookup term: %s" % term)
            lookupfile = self.find_file_in_search_path(variables, 'templates', term)
            display.vvvv("File lookup using %s as file" % lookupfile)
            if lookupfile:
                b_template_data, show_data = self._loader._get_file_contents(lookupfile)
                template_data = to_text(b_template_data, errors='surrogate_or_strict')
                
                searchpath = variables.get('ansible_search_path', [])
                if searchpath: