[FIX] Minor fix for r51994 - don't add a starting slash every time as that breaks relative links for tikis in subdirectories

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52023 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] ajax: Strip get params from ajax referrers as new ones will be added from the params (leading to double question mark issues etc)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52024 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] ajax: Split assignment and test to make things clearer (thanks nelsonko)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52025 b456876b-0849-0410-b77d-98878d47e9d5