Added PHP for spam protection & added HTML subject menu & Rated? checkbox

Spam on our site is any answer without an explanation. Examples are "lkj lkj lkj lkj" "A" "house" "gravity" As of now this is on the GUI side only, when tutors view their answers, spam answers are flagged as "Discarded...Explanation" Spam is computed by a vowel/consonant ratio. By preventing one/two-word answers, SnapStudents are getting explanations, not just answers.