Merge pull request #39 from miller/master

update README.md
Merge pull request #40 from miller/master

update README.md
Merge pull request #43 from miller/master

add define/create/get method in model
add example;
modify readme
merge mapapp @miller

仅merge部分问题。
Update README.md
Merge pull request #17 from BaiduFE/master

sync master