[SEC] installer: Remove one log action that can cause errors and minor changes to other log messages to be more useful; convert more $_REQUESTS to $_POSTS by converting more queries to forms

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@50345 b456876b-0849-0410-b77d-98878d47e9d5