Request: Add media query breakpoints as variables to variables.less

[fatcrobat]

Is it possible to add the following to variables.less, it makes media query handling much more compfortable.

@xs: ~"(max-width: @{screen-xs-max})";
@sm: ~"(min-width: @{screen-sm-min}) and (max-width: @{screen-sm-max})";
@md: ~"(min-width: @{screen-md-min}) and (max-width: @{screen-md-max})";
@lg: ~"(min-width: @{screen-lg-min})";

@sm-min: ~"(min-width: @{screen-sm-min})";
@md-min: ~"(min-width: @{screen-md-min})";
@lg-min: ~"(min-width: @{screen-lg-min})";

@xs-max: @xs;
@sm-max: ~"(max-width: @{screen-sm-max})";
@md-max: ~"(max-width: @{screen-md-max})";

Usage example:

@media @xs{
.container{
  padding-left: 0;
  padding-right: 0;
}
}

Thanks for having bootstrap. 👍

[cvrebert]

Approximate duplicate of #13014, a variation of which is already part of Bootstrap v4's code.