BugTrack2/366 Output 'X-Robots-Tag: nofollow' header on nofollow page

BugTrack2/366 Output 'X-Robots-Tag: nofollow' header on nofollow page

Internet search engines should not index PukiWiki default contents
(i.e. PukiWiki plugin manuals) and non-'read' pluing output (ie: Edit).
So we need to send "nofollow, noindex" marks to search engines.

Previously PukiWiki outputs "robots: nofollow,noindex" meta info
by HTML meta header contained in the default skin file.
Therefore if administrators customize skin file or use other skin,
they failed to tell "nofollow,noindex" to search engines.

In order to resolve this issue, PukiWiki engine now output
HTTP header 'X-Robots-Tag: nofollow,noindex' if the content should
not be cached.

We can tell right index policy to search engine crawlers
regardless of skin file.