Addunittests

I might have misunderstood the purpose of this method, but it looked to me like the 'check flagged terms' method should return true if the content is ok and false if it's not, such that the output of the validate method would be true if the content was worth sanitizing. I changed this method because the 'check no flagged terms returns true if content is not flagged' test I wrote failed with the original version.