Making 9.x LTS search interface be like in 10.x and 11.x (not an exact backport of r46624) As per discussion at http://thread.gmane.org/gmane.comp.cms.tiki.devel/29609 and http://tiki.org/Profiles+Team, to have more robust default settings, changing the default from Unified Search to MySQL Full Text Search, which AFAIK, never has any issues, even on shared hosting. Also, improving the documentation and putting Unified Search as an advanced feature. Labelling MySQL Full Text Search as Basic Search and Unified Search as Advanced Search

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/9.x@46626 b456876b-0849-0410-b77d-98878d47e9d5