topic create, show and list.
add topic feature test.
fixed uploaded photo can not display after deploy.
create topic reply, list replies.
add topic reply feature test.
upload photo of topic and reply, its content can be markdown.
show time distance.
add index.
remove unnecessary pending.
Merge pull request #394 from saberma/saberma-bug/fixed-uploaded-photo-can-not-display-after-deploy

修正部署后图片无法显示的问题
add encoding: utf-8.
limit sms to 100 words.
Merge pull request #397 from saberma/saberma-enhancement/adjust-sms-limit

活动变更内容字数限制为100字
Merge pull request #395 from saberma/saberma-feature/383-mini-bbs

加入迷你论坛
save user phone.
add user phone feature test.
add user phone javascript test.
wait 60 second to re-send the phone code.
user phone code can send 10 times a day.
show user phone blank notification.