fix a bug for space.
Merge branch 'master' into wujun_wp
Merge branch 'master' into wujun_wp
修改wp8 聊天的文档。
Added app search rest api.
Added search api link to rest_api.md
fix {{}} expression display
md {{}}
fix md
readme
Merge pull request #22 from lbt05/master

v2.6.8
Merge pull request #21 from leancloud/wujun_wp

Wujun wp
Review android section.
Review ios.
fixed merge conflict.
Revert selfId.
Updated title.
Fixed typo.
Fixed null.
Fixed link.