Merge pull request #250 from forrest-mao/master

fix lit desc
bodySha1
Merge pull request #251 from SunRunAway/patch-2

callbackurl 支持魔法变量， 新加魔法变量 $(bodySha1) (只能用于 callbackurl)
Update segtime.md
7.0
android sdk 7，保留android-sdk-6链接
Merge pull request #252 from simon-liubin/master

7.0 android-sdk文档
python sdk 7，保留python-sdk-6的链接
android-sdk-7 微调
Merge pull request #253 from simon-liubin/master

7.0 sdk 文档调整
Merge pull request #254 from forrest-mao/master

add mimetype spec of mkfile
Update avthumb.md
Merge pull request #255 from forrest-mao/master

fix ueditor dn link
魔法变量适用范围更改
Merge pull request #256 from simon-liubin/master

魔法变量适用范围更改
Update pm3u8.md
Merge pull request #257 from lintianzhi/patch-15

Update pm3u8.md
Update pm3u8.md
Merge pull request #258 from lintianzhi/patch-15

Update pm3u8.md
Merge pull request #260 from forrest-mao/master

rm img quality