new json problems
energy balance 8 has been added as authentic set 6th problem
Updated description for set 1 problems
Updated description and lessonsLearned for set 2 problems
Updated description and lessonsLearned for set 3 problems
Updated description and lessonsLearned for set 4 problems
Updated description and lessonsLearned for set 5 problems
Merge branch 'master' into jingxian2