I was starting to hack together a counter part to ExtractWikiPageLinks()

I was starting to hack together a counter part to ExtractWikiPageLinks()
to extract the external links (for the XML-RPC interface).  In so doing,
discovered yet more bugs in the current ExtractWikiPageLinks().
(Bumpy words within raw URLs and interwiki links were being counted
as links when they shouldn't have been.)

So instead converted ExtractWikiPageLinks() to ExtractLinks() which finds
both internal and external links.   ExtractWikiPageLinks() is now a wrapper
around ExtractLinks().  (Also new function ExtractExternalLinks() is another
wrapper.)

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@2345 96ab9672-09ca-45d6-a79d-3d69d39ca109