improve quizIntro.jsp, change some schema

changed schema for Activity and Quiz to allow for duration and
description. added many methods in mysqlManager
Merge branch 'master' of https://github.com/EllenSebastian/cs108project

Conflicts:
	quizWebsite/src/quizWebsite/Achievement.java
	quizWebsite/src/quizWebsite/Activity.java
Merge branch 'master' of https://github.com/EllenSebastian/cs108project

Conflicts:
	quizWebsite/WebContent/userPage.jsp
	quizWebsite/build/classes/quizWebsite/Activity.class
	quizWebsite/build/classes/quizWebsite/UserManager.class