Add feature for reset rem with media query and property.

[Akimyou]

Px2rem is awesome, thank you.

I added new features to px2rem.

• remResetMeidas: Specifies the media query condition and properties, automatically generated media query code for reset rem
• remResetPropertys: Specifies the properties, the associated property values ​​will not be generated rem

It seems that the functions are similar to /**/, but they can be configured globally, especially to avoid code repeated media queries.

remResetMeidas can be used to improve the reading experience of small-screen mobile phones. Many designs use 375 as the standard width. After using the rem scheme, the mobile phone with a width >= 375 is generally normal, but the size of a mobile phone with a size <375 is relatively small (eg iPhone SE). So width <375 (width less than design draft) can use it to reset all font-size rem.

remResetPropertys can be use to reset all border, etc...

Thanks.

[coveralls]

Coverage remained the same at 100.0% when pulling 0ace1e8 on xianyukeji:master into 20e30fa on songsiqi:master.

[coveralls]

Coverage remained the same at 100.0% when pulling b406280 on xianyukeji:master into 20e30fa on songsiqi:master.

[Akimyou]

This is the preview npm pkg.
https://www.npmjs.com/package/xianyukeji-px2rem

[Akimyou]

This is the preview postcss plugin npm pkg for xianyukeji-px2rem.
https://www.npmjs.com/package/xianyukeji-postcss-px2rem