added more detailed description for exercise and solution to exercise, not finalise
remove onload() from body since these pages do not need it
made font size of solution smaller so they are not too obvious
added more animation divs according to the requirements of the exercise, changed the asscoiating css position to relative
made small changes to content of exercise as well as solution, finalised
Merge remote-tracking branch 'upstream/master'
disabled spelling check in textareas for all exercise files
Merge pull request #34 from sandyphan/master

added more contents, added a few more anim divs for exercises