BUGFIX: the search was only operating on the part of the tree (as returned by markPartialTree), now it searches globally
MINOR: renamed 'filter' to 'search'
git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/branches/2.4@97031 467b73ca-7a2a-4603-9d3b-597d59a354a9