Identical nested close tags not correctly identified

[premasagar]

E.g. for the template:

{{_content}}
    {{_content}} foo {{/_content}}
{{_/content}}

• an error would arise, because the outer _content block's closing token is erroneously assumed to be the first {{/_content}} token.

Line 224:

closePos = templateEnd.indexOf(closeToken);

This instead needs to walk through multiple open tokens, and only identify a matching closing token.