Item12746: amend doc reflecting recent experience installing latest plugin

git-svn-id: http://svn.foswiki.org/trunk@17278 0b4bb1d4-4e5a-0410-9cc4-b2b747904278
Item12746: spatial not spacial

git-svn-id: http://svn.foswiki.org/trunk@17279 0b4bb1d4-4e5a-0410-9cc4-b2b747904278