[REVERT]Revert r52163 as button class changes (in articles and blogs) were mostly to navigational buttons

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52181 b456876b-0849-0410-b77d-98878d47e9d5
[FIX]Improve r52164: Remove non-default button class for navigational buttons in Newsletters

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52182 b456876b-0849-0410-b77d-98878d47e9d5