Added parameter rec=1 to JS built requests to piwik.php

We can imagine other usage of rec=1 parameter, for example to force tracking of non-JS visits on myspace, facebook, or other JS disabled environments

git-svn-id: http://dev.piwik.org/svn/trunk@1931 59fd770c-687e-43c8-a1e3-f5a4ff64c105