[ticket/13795] Modify core event in posting to include poll data
Modified the core.posting_modify_template_vars event in posting.php
to extend the content of the page_data array to include poll data.
That required moving the event and merging the new set of template vars.
Also include the poll variable in the parameter list for event
core.posting_modify_submission_errors, as it was missing, and any
modification here on post_data for poll related data is silently
ignored. Added correct @change tags to both events.
[ticket/13786] Add events to add MCP post options
Three new events are included:
1) Core event to perform new moderator action in includes/mcp/mcp_post.php
2) Core event to add/modify template data in includes/mcp/mcp_post.php
3) Template event to present new options in template/mcp_post.html
Remove extra template variable around the new event.
