add more-css

`more-css` is a pre-compiler & compressor,
It do more aggressive merging on minifying CSS like this:
```css
.a{margin:0;padding:0}.b{margin:0;color:#FFF}.c{padding:0;color:#FFF}
```
to
```css
.a,.c{padding:0}.a,.b{margin:0}.b,.c{color:#FFF}
```
And this is not allowed because `margin` is conflict:
```css
.a{margin:0;padding:0}.b{margin-top:0}.c{margin:0;padding:0}
```
to
```css
.a,.c{padding:0}.a{margin:0}.b{margin-top:0}.c{margin:0}
```
Also this is not allowed because the selector is longer than the css value
```css
.aaaaaa{margin:0;padding:0}.b{margin:1}.ccccccc{margin:0;padding:0}
```
to
```css
.aaaaaa{margin:0;padding:0}.b{margin:1}.ccccccc{margin:0;padding:0}
```