1. added pluginname_comment_validate callback to comments api
2. change permission callback defaults to false
3. Tidied up serveal areas of comments and implemented callback to
ignore system permissions for view (credits to Sam Hemelryk)
AMOS BEGIN
MOV [modulerejectcomment,error],[callbackrejectcomment,error]
AMOS END
Major tasks undertaken in this patch:
* New format_text argument, overflowdiv.
* New page layout Report.
* Review of all format_text calls.
* Added support for the report layout to all themes.
* Changed forum post display from tables to divs.
