Merge pull request #2 from liwenzhu/develop

feature sign in and sign up
Merge pull request #4 from liwenzhu/develop

add feedback email.
Merge pull request #5 from liwenzhu/develop

fix item is too long problem.
Merge pull request #6 from liwenzhu/develop

add ui delete list.
Merge pull request #7 from liwenzhu/develop

remove list from mongo
add user system, change to personal when user login.
Merge pull request #8 from liwenzhu/master

add user system