update explore.html, add explore_main.css, jquery.wookmark.js, jquery.imagesloaded.js  in /static
remove xiaolitest.html
replace jquery.imagesloaded.js with jquery.imagesloaded.min.js, jquery.wookmark.js with jquery.wookmark.min.js, update explore.html
Merge branch 'master' of https://github.com/leituo56/CMPE272-Group6 into Dev_TuoLei